Overt Neurological Deficits Research Articles

Bilateral Agenesis of the Hippocampal Dentate Gyrus in a Neurologically Normal Adult

Ontogenic development of granule cells in the hippocampal dentate gyrus is influenced by genes including WNT3, EMX2, NEUROD, and LEF1. Dentate granule cells continue to be generated from stem cell precursors postnatally and during adult life, and are implicated in normal and abnormal neurological function. Developmental privation of dentate granule cells is rare and essentially always occurs in the context of other neurodevelopmental abnormalities. We have found no previous reports of severe, selective agenesis of dentate granule cells in humans. A gross and microscopic examination of the brain included appropriate histochemical and immunohistochemical preparations and examination of the hippocampal formation at multiple levels bilaterally. This neurologically normal 82-year-old man was found to have bilateral agenesis of the hippocampal dentate gyrus, no identifiable dentate granule cells, and moderate disorganization of the pyramidal cell layer of Ammon's horn. We found no neurodevelopmental abnormalities outside the hippocampus. The hippocampal architectural alterations in this patient are similar to those associated with a murine Lef1 mutation, but our human case does not have the other congenital deficits reported in the Lef1-null mouse. Bilateral agenesis of the hippocampal dentate gyrus, and apparent failure of regeneration of dentate granule cells from stem cells in adult life, may occur without overt clinical neurological deficits.

Diagnosis of chronic radiating lower back pain without overt focal neurologic deficits: what is the value of segmental nerve blocks?

The purpose of this paper is to discuss the value of spinal segmental nerve blocks in establishing diagnosis in chronic lower back pain patients with pain radiating to the leg without overt focal neurologic deficits. These patients represent a large population. Establishing diagnosis is often problematic and the effectiveness of presently available therapies is low. Indication, character of radiating pain, pain diagnosis, factors influencing segmental nerve blocks, reliability of segmental nerve blocks in diagnosing pain, recently performed studies on the reproducibility of segmental nerve block effects and considerations with respect to ‘segmental pain’ will be discussed herein.

Diagnosis of chronic radiating lower back pain without overt focal neurologic deficits: what is the value of segmental nerve blocks?

Diagnosis of chronic radiating lower back pain without overt focal neurologic deficits: what is the value of segmental nerve blocks?

Biochemical markers of cerebrovascular injury in sleep apnoea syndrome.

Sleep apnoea syndrome (SAS) is a known risk factor for vascular diseases and stroke. Structural brain damage, manifesting as an overt neurological deficit or more subtly as cognitive dysfunction, is a frequent symptom in SAS. The presence of a biochemical marker of cerebral injury would be of great benefit in SAS to screen for even small brain damage and to monitor efficiacy of therapy. Therefore, in 10 patients with mild SAS (age 50.8+/-9.9 yrs, respiratory disturbance index (RDI) 18+/-3.6, lowest arterial oxygen saturation (min Sa,O2) 80.5+/-4.06%) and nine patients with severe SAS (age 50.3+/-11.5 yrs, RDI 75.4+/-21.7, min Sa,O2 56.56+/-14.58%), serum concentrations of neuron-specific enolase (NSE), S-100beta protein, and beta-trace were measured just before and after sleep using commercially available assays. Only serum levels in the normal range could be found, independent of when the blood was taken or the degree of SAS. Structural cerebral injury caused by sleep apnoea syndrome in patients without neurological symptoms or previous cerebrovascular events may be too small to produce a measurable increase in S-100beta, neuron-specific enolase and beta-trace serum concentrations or subclinical cerebral damage may be outside the lower detection limits of the analytical methods which were used. There is a need for biochemical markers and more sensitive methods for detecting small cerebral injury in sleep apnoea syndrome.

Lower urinary tract function in ambulatory children with spina bifida.

To investigate lower urinary tract function in ambulatory children with myelomeningocele. The urological course of 45 children with myelomeningocele who walked either independently (19 children) or with ankle-foot orthotics (26 children) was reviewed. Follow-up ranged from 9 months to 13.5 years (mean 4.75 years). A normal pattern of voiding was observed both clinically and during urodynamic evaluation in only three of the 45 children, with the remainder displaying neurogenic lower urinary tract dysfunction. The independent walkers and those with orthotics did not differ in the spectrum of lower urinary tract dysfunction or other variables. Those patients with persistent incontinence underwent an initial urodynamic evaluation when older (mean 3.7 years versus 6.4 weeks in those who were continent). Ambulatory children with myelomeningocele suffer the full spectrum of lower urinary tract dysfunction. Given the potential danger of untreated lower urinary tract dysfunction, ambulatory children with myelomeningocele should receive the same diagnostic and therapeutic attention as their peers with more overt neurological deficits.

Stroke during coronary artery bypass grafting using hypothermic versus normothermic perfusion

Does the abandonment of hypothermic perfusion during cardiopulmonary bypass compromise cerebral protection and thus lead to a higher incidence of stroke? From 1987 to June 1993, 2,585 consecutive patients underwent myocardial revascularization using warm-body (perfusion at 37 degrees C), cold-heart (cold cardioplegic arrest) surgical technique and were followed for new overt neurologic deficits. Perfusion pressure was maintained between 50 and 70 mm Hg, and hematocrit was kept around 20%. There were 25 operative deaths (1%) in this normothermic group, and new neurologic deficits developed after operation in 25 patients (1%). These results were compared retrospectively with those in 1,605 patients who underwent myocardial revascularization between 1980 and 1986 with moderate hypothermic (25 degrees to 30 degrees C) perfusion, the same surgical team, and similar operative techniques. The normothermic group included more elderly patients, more patients with left ventricular dysfunction and unstable angina, and more frequent use of an internal mammary artery conduit. Neurologic complication rates were 1% and 1.3% for the normothermic and hypothermic perfusion groups, respectively. Risk factors for stroke that were identified included age greater than 70 years, severity of aortic arch atherosclerosis, and severe hypotension in the perioperative period. Thus, in a large clinical series, the incidence of overt neurologic injuries was found to be no higher with normothermic perfusion than with hypothermic perfusion.

Response of Paget's disease to porcine and salmon calcitonins: Effects of long-term treatment

Multiple clinical, biochemical and immunologic variables were measured in 49 patients with Paget's disease during 4 to 41 months (mean, 25 months) of treatment with porcine (PCT) or synthetic salmon calcitonin (SCT) or both. Mild nausea and dermal reactions occurred in 20 per cent of the patients and were generally transient. Skeletal and radicular pain, and overt neurologic deficits were moderately to dramatically relieved in 75 per cent of the patients. Maximal clinical benefits were achieved during the first 6 to 12 months of treatment, with only one fifth of the patients experiencing intermittent exacerbations of pain during the 2nd and 3rd years of treatment. Three examples of dramatic roentgenologic improvement were observed. SCT doses of 50 MRC units three times a week generally were as effective as 100 MRC units three times a week or daily. Dissociation among the clinical effects, the decrease in serum alkaline phosphatase and the decrease in urinary hydroxyproline were common. Binding antibodies developed in 60 per cent of the patients treated with PCT and in 30 per cent of those treated with SCT; however, SCT-binding antibodies usually were present in higher titer and with a greater frequency of SCT neutralization activity. No correlations were present between the development of antibodies and the incidence of biochemical rebounds or the failure of increased doses of SCT to renew biochemical effects. No evidence of increased secretory activity of the parathyroid glands was observed in 10 patients with biochemical rebounds. These data demonstrate the feasibility and efficacy of continuous long-term therapy with calcitonin on an outpatient basis, and SCT may be the treatment of choice for Paget's disease.