Chronic Compressive Neuropathy Research Articles

Patient Reported Outcomes using PROMIS after Tarsal Tunnel Release Surgery

Category: Other Introduction/Purpose: Tarsal tunnel syndrome is an entrapment neuropathy of the tibial nerve and its branches in the tarsal tunnel. The literature on surgical release of the tarsal tunnel shows variable outcomes with no studies reporting validated patient reported outcomes. We aim to determine clinical response after tarsal tunnel release using the Patient-Reported Outcomes Measurement Information System (PROMIS). Methods: Under an IRB-approved protocol, CPT code 28035 was used to identify patients who underwent isolated tarsal tunnel release (TTR) between 1/1/2015 and 12/15/2022 at a single institution. Patient demographic data and PROMIS CAT physical function (PF), pain interference (PI), and depression scores were prospectively collected at the initial pre-operative clinic visit and in follow-up throughout the episode of care after TTR. The validated distribution-based method (1/2 sd) was used to assess minimal clinically important difference (MCID). Bivariate analysis was used to determine the postoperative recovery after TTR. Statistical significance was set at p< 0.05. Results: A total of 39 patients who underwent tarsal tunnel release were included. The mean age was 49.1 years (19.44-70.75 years) and mean follow-up was 280.9 days (23-1,459 days). The mean PROMIS PF score improved from 38.97 preoperatively to 46.17 postoperatively (p-value= 0.0024). The mean PROMIS PI score improved from 63.75 preoperatively to 57.65 postoperatively (p-value < 0.001). The mean PROMIS depression score improved from 49.78 preoperatively to 43.85 postoperatively (p-value < 0.001). The mean t-score change (pre to post-operation) was 7.2 for PF, -6.1 for PI, and -5.93 for depression. MCID thresholds were calculated as PF increase of 4.7; PI decrease of 3.9; and Depression decrease of 5.1. Fourteen (35%), 24 (62%), and 27 (69%) patients reached MCID for PF, PI, and depression, respectively. Conclusion: This study provides validated outcomes after TTR. Though there is improvement after surgery, the patients still experience some pain and physical limitations. Interestingly, the greatest gains were seen in depression symptoms supporting the idea that mental health is impacted in these chronic compressive neuropathy conditions.

Orbital panniculitis-like T-cell lymphoma and review of literature

A 27-year-old patient without a pertinent past medical history presented with chronic orbital inflammation and compressive optic neuropathy. Orbital biopsy with adequate histological and immunohistochemical staining was necessary to identify the disease as subcutaneous panniculitis-like T-cell lymphoma, a rare entity which has only been published as presenting in the orbit on four previous occasions. Immunohistochemical staining is necessary to differentiate the disease from a more benign condition, lupus erythematosus panniculitis, and a more malignant condition, primary cutaneous γδ T-cell lymphoma. The former can be managed with immunosuppression, while the latter may require more aggressive chemotherapy.

Microvascular neural blood flow assessment for a chronic nerve compression neuropathy mouse model by fluorescein angiography

ABSTRACT Background and aims Intraoperative fluorescence angiography with indocyanine green or fluorescein is used in ophthalmology and neurosurgery. However, there are few reports on the use of fluorescence angiography for peripheral neuropathy. This study aimed to assess the validity of fluorescein angiography (FAG) for peripheral nerve entrapment neuropathy. Methods We used an established model of chronic nerve compression (CNC) neuropathy in C57BL/6 mice by entrapping their left sciatic nerve with a silastic tube. Mice were assigned to the uninjured group (control), two-week CNC neuropathy group, four-week CNC neuropathy group, or six-week CNC neuropathy group. We then performed FAG to assess neural blood flow and quantified the peak of the luminance at the compression site with luminance analysis software. Following FAG, histological examinations using an anti-fluorescein antibody and Masson’s trichrome staining were performed to evaluate the area of fluorescein distribution and epineural fibrosis. Results The luminance in the CNC neuropathy groups was significantly lower than that in the control group. Histological analysis revealed the fluorescein positive areas in the CNC neuropathy groups were significantly smaller than that in the control group, and the epineural fibrosis areas in the CNC neuropathy groups were significantly larger than that in the control group. Conclusion We observed a significant decline of luminance in the CNC neuropathy groups, and the histological assessment was consistent with this result. FAG was found to be a valid method for assessing CNC neuropathy in mice.

Nerve decompression in diabetics with chronic nerve compression: update 2022

The number of people with diabetes worldwide has reached epidemic proportions. Diabetics are well-known to have chronic nerve compressions, and the prevalence of compressions exceeds 50% in those with neuropathy. The loss of sensation in the feet of people with diabetic neuropathy is the primary cause of their ulceration and amputation, as well as pain. The aim of this article is to update the reader on the current status of lower extremity nerve decompression in patients with diabetic neuropathy. A review of the history and literature related to the current approach to the patient with chronic nerve compression plus diabetic neuropathy was undertaken. The current evidence is overwhelmingly clear, in diabetics with neuropathy and a positive Tinel sign over the tibial nerve at the tarsal tunnel, that decompression, by neurolysis of lower extremity nerves, can relieve pain, restore sensation, and prevent ulceration and amputation. Furthermore, economic cost-benefit analysis by the Markov technique demonstrates that lower extremity nerve compression is not only cost-effective compared to standard medical care, but also increases the quality of life and life expectancy. The remaining barriers to acceptance and implementation of this proven surgical approach must lie in the education of physicians in training and re-education of diabetes educators, primary care providers and endocrinologists.

Epidemiology and approach in Carpal Tunnel Syndrom: An analysis of the impact on return on labor

Background: Carpal Tunnel Syndrome (CTS) is defined as a focal, chronic and symptomatic compressive neuropathy of the median nerve at the wrist. It is the most prevalent neuropathy in the population. The objective of the study to describe the epidemiological, clinical and occupational profile of patients with CTS who underwent median nerve neurolysis in the carpus and the Occupational Therapy intervention attended by the Sistema Único de Saúde (SUS). Methods: This is a descriptive study, carried out from january 2014 to december 2017 at Centro Estadual de Reabilitação e Readaptação Dr. Henrique Santillo (CRER), in the city of Goiânia, located in the Center-West region of Brazil. The Reference population covered the medical records of patients submitted to the surgical procedure and rehabilitation. During this period, 698 patients underwent surgery and rehabilitation, and the sample of 249 charts analyzed was defined by means of a sample calculation using the finite sample proportion test. A margin of error of 5% was considered in the calculation. Out-of-time-range patients and those with other associated hand injuries were excluded. Our study was approved by the Research Ethics Committee registered under number 97279.121. The data were analyzed with the aid of the SPSS 23 statistical package. In all analyzes, thes ignificancel evel adopted was 5% (p <0.05).Results: The demographic profile was composed of 223 women, representing 89.6% of the sample, in the age group between 40 and 59 years, being 74.7% of right-handed patients. Comorbidities were present in 63.1% of the patients and the main ones are Systemic Arterial Hypertension (SAH), Diabetes Mellitus (DM) and Fibromyalgia. The vast majority of cases were classified as severe or very severe staging. The labor distribution was categorized into 12 distinct groups, with workers doing domestic work prevailing. Conclusion: A greater bilateral involvement was observed in the studied sample, classified in the severe or very severe stages, which resulted in the surgical treatment and early intervention and systematization of occupational therapy, which favored the patient to be replaced in work activities in about 84, 7% of the cases surveyed.

Revision surgery for carpal and cubital tunnel syndrome

Carpal tunnel syndrome, acompressive neuropathy of the median nerve at the wrist and cubital tunnel syndrome, acompressive neuropathy of the ulnar nerve at the elbow, are the two most common peripheral nerve compression syndromes. Chronic compressive neuropathy of peripheral nerves causes pain, paraesthesia and paresis. Treatment strategies include conservative options, but only surgical decompression can resolve the mechanical entrapment of the nerve with proven good clinical results. However, revision rates for persistent or recurrent carpal tunnel syndrome is estimated at around 5% and for refractory cubital tunnel syndrome at around 19%. Common causes for failure include incomplete release of the entrapment and postoperative perineural scarring. Precise diagnostic work-up is obligatory before revision surgery. The strategy of revision surgery is first complete decompression of the affected nerve and then providing ahealthy, vascularized perineural environment to allow nerve gliding and nerve healing and to avoid recurrent scarring. Various surgical options may be considered in revision surgery, including neurolysis, nerve wrapping and nerve repair. In addition, flaps may provide awell vascularized nerve coverage in the case of recurrent carpal tunnel syndrome. In the case of recurrent cubital tunnel syndrome, anterior transposition of the ulnar nerve is mostly performed for this purpose. In general, revision surgery leads to improvement of symptoms, although the outcome of revision surgery is less favourable than after primary surgery and complete resolution of symptoms is unlikely.

Supercharge End-to-Side Anterior Interosseous-to-Ulnar Motor Nerve Transfer Restores Intrinsic Function in Cubital Tunnel Syndrome.

The supercharge end-to-side anterior interosseous nerve-to-ulnar motor nerve transfer offers a viable option to enhance recovery of intrinsic function following ulnar nerve injury. However, in the setting of chronic ulnar nerve compression where the timing of onset of axonal loss is unclear, there is a deficit in the literature on outcomes after supercharge end-to-side anterior interosseous nerve-to-ulnar motor nerve transfer. A retrospective study of patients who underwent supercharge end-to-side anterior interosseous nerve-to-ulnar motor nerve transfer for severe cubital tunnel syndrome over a 5-year period was performed. The primary outcomes were improvement in first dorsal interosseous Medical Research Council grade at final follow-up and time to reinnervation. Change in key pinch strength; grip strength; and Disabilities of the Arm, Shoulder and Hand questionnaire scores were also evaluated using paired t tests and Wilcoxon signed rank tests. Forty-two patients with severe cubital tunnel syndrome were included in this study. Other than age, there were no significant clinical or diagnostic variables that were predictive of failure. There was no threshold of compound muscle action potential amplitude below which supercharge end-to-side anterior interosseous nerve-to-ulnar motor nerve transfer was unsuccessful. This study provides the first cohort of outcomes following supercharge end-to-side anterior interosseous nerve-to-ulnar motor nerve transfer in chronic ulnar compression neuropathy alone and underscores the importance of appropriate patient selection. Prospective cohort studies and randomized controlled trials with standardized outcome measures are required. Therapeutic, IV.

Management of Recalcitrant Carpal Tunnel Syndrome.

Recalcitrant carpal tunnel syndrome presents a clinical challenge. Potential etiologies of persistent or recurrent symptoms after primary carpal tunnel release include incomplete nerve decompression, secondary sites of nerve compression, unrecognized anatomic variations, irreversible nerve pathology associated with chronic compression neuropathy, perineural adhesions, conditions associated with secondary nerve compression, iatrogenic nerve injury, or inaccurate preoperative diagnosis. Understanding the pertinent surgical anatomy and pathophysiology is essential toward developing an effective diagnostic and treatment strategy. A thorough clinical history and examination guide a comprehensive diagnostic evaluation that includes serial examinations, neurophysiologic testing, and imaging studies. Conservative treatment may provide symptomatic relief; however, surgical management involving revision neuroplasty, neurolysis, nerve reconstruction, and/or local soft-tissue flap augmentation may be indicated in refractory cases.

Muscle Fiber Type Changes in Lumbrical Muscles at Early Stages of Chronic Nerve Compression.

Chronic nerve compression (CNC) neuropathy is a common disease in the clinic and provokes paraesthesia, or numbness at early stage. The changes in muscle fiber composition and motor nerve terminal morphology in distal muscles were studied in this study. A well-established CNC model was used to assess the changes in the muscles. Behaviors were measured by von Frey filament test. The myosin heavy chain isoforms and neuromuscular junctions (NMJs) were stained by immunofluorescence to show the muscle fiber types composition and motor nerve terminals morphologic changes in the flexor digitorum longus (FDL) and lumbrical muscle. The fiber cross-sectional areas of different muscle fiber types were measured. The small-fiber degeneration of cutaneous nerve fibers was examined by detecting the protein gene product 9.5 (PGP9.5) with immunofluorescence. At 2nd month after compression, the proportion of type I and type II B fibers was markedly decreased, and that of type II A fibers was increased in the lumbrical muscle. There was no significant change in composition of muscle fiber types in FDL and NMJ morphology of FDL and lumbrical muscles. Intra-epidermal nerve fibre density (IENFD) declined at 2nd month after the compression. Our study reveals the morphological changes of the FDL and lumbrical muscle at an early stage of CNC. These findings may be helpful to understand muscle damage and pathophysiological development of the nerve compression, and provide new evidence for early treatment of CNC.

Barriers to Epineural Scarring: Role in Treatment of Traumatic Nerve Injury and Chronic Compressive Neuropathy.

The physiological limitations of neural regeneration make peripheral nerve surgery challenging to both the surgeon and the patient. Presence of nerve gaps and local wound factors may all influence outcome, suggesting that barriers to reduce perineural scarring, minimize fibrosis, and avoid ischemia would be beneficial. To examine the evidence supporting their use, we reviewed the autologous and commercially-available options for barriers against scarring around a nerve. Numerous clinical case series demonstrated the effectiveness and safety of local/rotational flaps and autologous vein wrapping when used in the presence of recurrent compressive neuropathy. Translational research in animal models supports the biocompatibility of commercially available nerve wraps following nerve repair. To date, there are no reports of clinical use of commercially available nerve wraps in acute nerve repair, but a growing number of case series demonstrate their effectiveness and safety in chronic compressive neuropathy. Limited clinical evidence exists to support the efficacy of vein or flap coverage in acute nerve repairs.

P346 Median nerve conduction across the wrist in GBS and CTS

Objectives Wrist is the only segment where both sensory and motor conduction studies of the same nerve can be applied together for two diseases with different pathophysiology: “carpal tunnel syndrome (CTS)”, a chronic compression neuropathy and “Guillain Barre syndrome (GBS)”, an acquired monophasic inflammatory neuropathy. This study aims to point out how GBS differs from CTS by means of median nerve conduction at wrist level. Methods Nerve conduction studies of GBS and CTS patients admitted to EMG lab between the years of 2013 and 2017 were reanalyzed in retrospective manner. Patients with prolonged median motor distal latency either unilateral or bilateral were included. For each group, 24 median nerve conduction studies were reevaluated. Orthodromic sensory response of median nerve which was recorded just proximal to carpal tunnel in response to 2nd digit stimulation and thenar eminence recorded median motor response were considered. Results Among the hands of CTS patients, only 1 sensory response could not be evoked however for GBS group, 7 out of 24 were absent ( p 0.05 ). In patients where both sensory and motor responses were elicited, GBS hands revealed significantly prolonged motor latencies (mean: 6.2 ± 1.85; range 4.2–11.6 versus mean: 4.86 ± 0.5, range 4.22–6.46) although their sensory conduction velocity was much faster (mean: 43.72 ± 9.25; range 32.4–60 versus mean: 35.8 ± 4.54; range 27.4–45.2). Conclusion In GBS, acquired conduction deficit leads to prolonged motor latency combined with absent sensory response. If sensory response was present, it tends to be conducted faster compared to CTS although the motor latency is profoundly prolonged.

Effects of decompression on behavioral, electrophysiologic, and histomorphologic recovery in a chronic sciatic nerve compression model of streptozotocin-induced diabetic rats.

PurposeTo determine susceptibility to decompression surgery in diabetic and nondiabetic peripheral neuropathy using a chronic compression neuropathy model.Materials and methodsTwenty-four streptozotocin-induced diabetic rats were randomly divided into three groups: group I, chronic compression of the left sciatic nerve for 4 weeks with decompression; group II, similar without decompression; and group III, sham exposing the sciatic nerve only. The other 24 nondiabetic rats were assigned to groups IV–VI, which received compression–decompression, compression, and the sham operation, respectively. Mixed-nerve-elicited somatosensory evoked potentials (M-SSEPs) and compound muscle action potentials (CMAPs) were measured to verify the compression neuropathy in the posttreatment follow-up. Behavioral observations in thermal hyperalgesia tests were quantified before electrophysiologic examinations. Treated and contralateral nerves were harvested for histomorphologic analysis.ResultsChronic compression of sciatic nerve induced significant reduction of amplitude and increment of latency of M-SSEP and CMAP in both diabetic and nondiabetic rats. Diabetic group changes were more susceptible. Decompression surgery significantly improved both sensory and motor conduction, thermal hyperalgesia, and the mean myelin diameter of the rat sciatic nerve in both diabetic and nondiabetic groups. Near full recovery of motor and sensory function occurred in the nondiabetic rats, but not in the diabetic rats 8 weeks postdecompression.ConclusionBehavioral, electrophysiologic, and histomorphologic findings indicate that decompression surgery is effective in both diabetic and nondiabetic peripheral neuropathy.

Erythropoietin is Neuroprotective During Ongoing Compression and Speeds Recovery Following Surgical Decompression in a Murine Model of Chronic Compression Neuropathy: N/A - Not a clinical study

Grant received from: American Foundation for Surgery of the Hand (Hand Surgeon Scientist Award), National Institute of Health grant (# 1 K08 AR060164-01A), Clinical and Translational Science Award (CTSA) grant (# UL1 TR000042), through the University of Rochester School of Medicine & Dentistry, University of Rochester CTSA award (# TL1 TR000096) from the National Center for Advancing Translational Sciences of the National Institutes of Health, University of Rochester Center Goldstein Grant, University of Rochester Laboratory Startup Fund, ART/CTSI Student Research Fellowship Award- salary support for Co-Investigator and medical student, Leigh Sundem There is no financial information to disclose. We previously described erythropoietin’s (EPO) effectiveness in ameliorating the effects of acute peripheral nerve crush. Pilot studies indicate that EPO therapy is an effective neuromodulatory agent for the treatment of chronic nerve compression (CNC) when used as an adjuvant to surgical decompression. This left open the question as to whether pretreatment with EPO during compression would be relevant in reducing the effect of ongoing compression. CNC injury was created in wild-type mice by placing an inert silastic sleeve around the sciatic nerve as in previous work. Decompression surgery was performed at 6 weeks with alternative mice receiving pre-decompressive treatment. Nerve conduction studies were performed weekly before decompression and every 48-hours thereafter until full recovery. Sixty mice were randomized into either a sham-surgery group, saline-treatment control (saline/saline), or 1 of 2 EPO-treatment groups with initiation of EPO at day 0 (EPO/EPO), or week 6 (saline/EPO) in conjunction with surgical decompression. Comparison of NCV was tested with one-way ANOVA followed by Student’s t-test in this dataset, which was normally distributed. During compression, there was a progressive decline in nerve conduction velocity (NCV) as compared to sham-injured animals where NCV remained normal (∼55 m/s) throughout the experiment (Figure 1A). NCV in saline-treated animals progressively decreased from normal (55.153.42 m/s) to a plateau (35.680.72 m/s) over 6 weeks of compression. This expected decline was strikingly attenuated in randomly-selected animals treated with EPO (NCV decreased from 54.091.67 to 45.771.08 m/s, P < 0.01) so that EPO-treated animals fared significantly better than saline-treated counterparts (P < 0.01). Following decompression, all animals recovered to a normal baseline NCV by day 15 (P = 0.74); however, the improvement in NCV observed was markedly accelerated within the first week post-decompression in the EPO-treated groups, and not in saline-treated counterparts (P < 0.01). Animals treated with EPO during both phases fully recovered in half the time as those treated only after decompression (day 5 versus day 9 P < 0.05). •This study supports the possibility of EPO as a neuroprotective agent during CNC injury in rodents and may support adjuvant use during active compression.•Improvement in electrophysiologic parameters is observed with EPO treatment during compression and decompression phases.•EPO may accelerate the natural recovery of decompressed nerves and protect against ongoing injury through the same mechanism, which suggests translational relevance.View Large Image Figure ViewerDownload Hi-res image Download (PPT) This research was supported by a 2013 Hand Surgeon Scientist Award from the American Foundation for Surgery of the Hand.

Ulnar neuropathy: evaluation and management.

Ulnar neuropathy is commonly encountered, both acutely after elbow trauma and in the setting of chronic compression neuropathy. Careful clinical evaluation and discerning evaluation of electrodiagnostic studies are helpful in determining the prognosis of recovery with nonoperative and operative management. Appreciation of the subtleties in clinical presentation and thoughtful consideration of the timing and type of surgical intervention are critical to optimizing outcomes after treatment of ulnar neuropathy. The potential need for decompression at both the cubital tunnel and Guyon's canal must be appreciated. Supplementation of decompression with supercharged end-to-side nerve transfer can expedite motor recovery of the ulnar intrinsic muscles in the appropriately selected patient. The emergence of nerve transfer techniques has also changed the management of acute ulnar nerve injuries.

Adipose-derived Stem Cells as a Potential Additive Therapy in Chronic Compression Neuropathy in Rodents: a Diffusion Tensor Imaging Study

IntroductionCompression neuropathy and nerve root compression are a leading cause of morbidity as well as a major cause of work impairment. Surgical and conservative treatments are widely used but there is still a lack of long-lasting effects. We seek to provide an additive therapy consisting of injected adipose-derived stem cells (ASCs) in the epineurium of a chronic nerve compression rodent model.In animal studies, evaluation of peripheral nerve injury and therapy monitoring is commonly performed using clinical scoring and histopathological workup. Recent developments in magnetic resonance imaging allow for the direct evaluation of nerve fiber integrity. Here we present the evaluation of this imaging method, diffusion tensor imaging (DTI) in the context of chronic sciatic nerve compression. Material and MethodsWe created a compressive lesion with a polymer clip on the left sciatic nerve of Sprague-Dawley rats. 0.5 million ASCs were injected in the epineurium under ultrasound guidance two weeks after the crush injury in a first group. The second group was injected with culture medium as control. The clips were removed in a third group who benefited from an intraoperative injection of ASCs and a fourth group underwent the same procedure but received the sham injection. Gait analyses with calculation of the Sciatic-Function-Index using a computed track were performed before the cells or sham injections as well as after two and four weeks. Two weeks post injection, respectively four weeks, post-mortem imaging was acquired on a 3-Tesla scanner. The Fractional Anisotropy (FA), a measure of fiber integrity, was measured for the proximal and distal part of the lesion and for the contralateral nerve. Afterwards, histomorphometry of cross sections of the nerve, histochemistry for muscle fiber typing and calculation of the gastrocnemius muscle weight ratio were undertaken. ResultsThe FA showed no differences between the injured and uninjured side at the proximal site. Distally, the FA was clearly reduced on the injured side. The FA in the group treated with ASCs who underwent clip removal was significantly higher as well as the FA ratio (distal value/ proximal value). These findings could be correlated with clinical and histological analyses that showed faster regeneration and faster clinical recuperation in this group associated with reduced muscle atrophy. ConclusionASCs alone seem to be insufficient to provide a clinically relevant treatment in this context of severe crush injury. Nonetheless, regenerative cells could be an interesting additive therapy after surgical decompression. Furthermore, our results indicate that DTI may be used to quantitatively assess sciatic nerve injury after treatment using ASCs in a rat model.

Neuroprotective Potential of Erythropoietin as an Adjuvant to Decompression for Chronic Compression Neuropathy: N/A - Not a clinical study

Neuroprotective Potential of Erythropoietin as an Adjuvant to Decompression for Chronic Compression Neuropathy: N/A - Not a clinical study

Clinical feature of chronic compressive optic neuropathy without optic atrophy

To investigate the clinical feature of the chronic compressive optic neuropathy without optic atrophy. Retrospective cases series study. The clinical data of 25 patients (37 eyes) with chronic compressive optic neuropathy without optic atrophy, treated in Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, from October, 2005 to March, 2014, were collected. Those patients had been showing visual symptoms for 6 months or longer, but missed diagnosed or misdiagnosed as other eye diseases due to their normal or slightly changed fundi. The collected data including visual acuities, visual fields, neuroimaging and/or pathologic diagnosis were analyzed. Among the 25 patients, there were 5 males and 20 females, and their ages range from 9 to 74 years [average (47.5 ± 13.4) years]. All patients suffered progressive impaired vision in single eye or both eyes, without exophthalmos or abnormal eye movements. Except one patient had a headache, other patients did not show systemic symptoms. The corrected visual acuities were between HM to 1.0, and their appearances of optic discs and colors of fundi were normal. After neuroimaging and/or pathological examination, it was proven that 14 patients suffered tuberculum sellae meningiomas, 5 patients with hypophysoma, 3 patient with optic nerve sheath meningioma in orbital apex, 1 patient with cavernous hemangioma, 1 patient with vascular malformation in orbital apex and 1 patient with optic nerve glioma. Among the 19 patients whose suffered occupied lesions of saddle area, 14 patients underwent visual field examinations, and only 4 patients showed classic visual field defects caused by optic chiasmal lesions. Occult progressive visual loss was the most important clinical feature of the disease.

Macular spectral domain optical coherence tomography findings in Tanzanian endemic optic neuropathy

Bilateral optic neuropathy in Dar es Salaam is now considered endemic and is estimated to affect 0.3-2.4% of young adults. The condition is characterized by a subacute bilateral loss of central vision of unknown aetiology. Findings of spectral domain optical coherence tomography have not previously been reported for these patients. All patients diagnosed with endemic optic neuropathy over a 2-year period at the Muhimbili National Hospital underwent spectral domain optical coherence tomography macular imaging. Scans were graded qualitatively for severity of retinal nerve fibre layer loss as well as the presence of microcystic macular changes, which have not previously been described in this condition. Of the 128 patients included (54.7% male; median age 20 years), severe retinal nerve fibre layer loss was found in 185 eyes (74.0%). There was full concordance in retinal nerve fibre layer thickness between the two eyes in 113 (91.1%) patients. Microcystic macular spaces were found in 16 (12.5%) patients and were bilateral in nine (7.0%) individuals. These changes were typically more prominent in the nasal than the temporal macula, predominantly involving the inner nuclear layer, and often occurred in an annular configuration that was evident on en face infra-red imaging, though not discernible on colour fundus photography or clinically. All patients with microcystic macular changes had severe thinning of the retinal nerve fibre layer (P = 0.02). Four patients in whom cystic spaces were demonstrated had sequential scans, and there was no detectable alteration in the configuration of these changes over a period of up to 16 months. This is the first study to document optical coherence tomography findings in endemic optic neuropathy. We have observed symmetrical severe loss of the caeco-central projection (papillomacular bundle) with otherwise well-preserved macular architecture. Also, we have observed microcystic retinal changes in a significant proportion of patients, which were associated with severe retinal nerve fibre layer loss. Similar changes have recently been reported from optical coherence tomography images of patients with multiple sclerosis, relapsing isolated optic neuritis, dominant optic atrophy, Leber's hereditary optic neuropathy and a patient with a chronic compressive optic neuropathy, supporting the hypothesis that this may be a non-specific phenomenon secondary to ganglion cell death. The correspondence of the changes to an annulus discernible on infra-red en face imaging, but not using other conventional retinal imaging techniques highlights the potential usefulness of this modality.

Predictive Factors for Vision Recovery after Optic Nerve Decompression for Chronic Compressive Neuropathy: Systematic Review and Meta-Analysis

Objectives Surgical optic nerve decompression for chronic compressive neuropathy results in variable success of vision improvement. We sought to determine the effects of various factors using meta-analysis of available literature. Design Systematic review of MEDLINE databases for the period 1990 to 2010. Setting Academic research center. Participants Studies reporting patients with vision loss from chronic compressive neuropathy undergoing surgery. Main outcome measures Vision outcome reported by each study. Odds ratios (ORs) and 95% confidence intervals (CIs) for predictor variables were calculated. Overall odds ratios were then calculated for each factor, adjusting for inter study heterogeneity. Results Seventy-six studies were identified. Factors with a significant odds of improvement were: less severe vision loss (OR 2.31[95% CI = 1.76 to 3.04]), no disc atrophy (OR 2.60 [95% CI = 1.17 to 5.81]), smaller size (OR 1.82 [95% CI = 1.22 to 2.73]), primary tumor resection (not recurrent) (OR 3.08 [95% CI = 1.84 to 5.14]), no cavernous sinus extension (OR 1.88 [95% CI = 1.03 to 3.43]), soft consistency (OR 4.91 [95% CI = 2.27 to 10.63]), presence of arachnoid plane (OR 5.60 [95% CI = 2.08 to 15.07]), and more extensive resection (OR 0.61 [95% CI = 0.4 to 0.93]). Conclusions Ophthalmologic factors and factors directly related to the lesion are most important in determining vision outcome. The decision to perform optic nerve decompression for vision loss should be made based on careful examination of the patient and realistic discussion regarding the probability of improvement.

Microcystic macular degeneration from optic neuropathy

Sir, We read with great interest the article by Gelfand et al. (2012) in the June issue of Brain . The authors described in detail vacuolar macular changes in the inner nuclear layer of patients with multiple sclerosis. This ‘microcystic macular oedema’ was associated with decreased visual acuity and a higher disability score. We found similar microcysts in the macular inner nuclear layer of a 13-year-old male suffering from neurofibromatosis type 1 and chronic compressive optic neuropathy in both eyes due to optic glioma (Fig. 1). Since the incidental finding of the glioma 15 months ago, the bilateral microcystic macular inclusions remained unchanged and vision was stable at one …