Pyramidal Tract Dysfunction Research Articles

Developmental dysgraphia is often associated with minor neurological dysfunction in children with developmental coordination disorder (DCD)

Children with developmental coordination disorder (DCD) are particularly affected by handwriting disorders, which remain poorly understood and are not clearly defined. The aim of our study is to provide a better understanding of handwriting disorders, and specifically of dysgraphia in children with DCD. Sixty-five children with DCD (5-15 years), enrolled according to DSM-5, were assessed with handwriting testing and standardized assessments of neuropsychological, neurovisual, MRI and neuropsychomotor functions, with special attention paid to muscular tone examination. While handwriting disorders were strongly represented in our sample of children with DCD (89%), dysgraphia appeared uncommon (17%) and was closely related to several specific dysfunctions of laterality establishment; mild pyramidal tract dysfunction with distal phasic stretch reflex (PSR) in lower limbs; digital praxis slowness (both P<0.05). In our sample, dysgraphia was closely related to minor neurological dysfunction (MND) suggesting a disturbance of motor control at the level of the corticospinal motor pathway. This highlights the uncommon character of dysgraphia in children with DCD for which diagnosis should be made through a particular attention to evaluation of MND with muscular tone examination. This consideration, both in the research setting and in clinical practice, appears necessary to avoid inaccurate clinical diagnosis and to optimize appropriate therapeutic management.

Progression of corticospinal tract dysfunction in pre-ataxic spinocerebellar ataxia type 2: A two-years follow-up TMS study

ObjectiveCorticospinal tract (CST) dysfunction is common in the pre-ataxic stage of spinocerebellar ataxia type 2 (SCA2) but quantitative assessment of its progression over time has not been explored. The aim of this study was to quantify the progression of CST dysfunction in pre-ataxic SCA2 using transcranial magnetic stimulation (TMS). MethodsThirty-three pre-ataxic SCA2 mutation carriers and a 33 age- and gender-matched healthy controls were tested at baseline and 2-years follow-up by standardized clinical exams, validated clinical scales, and TMS. ResultsPre-ataxic SCA2 mutation carriers showed a significant increase of resting motor thresholds (RMT) to abductor pollicis brevis (APB) and tibialis anterior (TA) muscles, and of central motor conduction time (CMCT) to TA at 2-years follow-up, over and above changes in healthy controls. The changes in the pre-ataxic SCA2 mutation carriers were independent of the presence of clinical signs of CST dysfunction at baseline, and independent of conversion to clinically definite SCA2 at 2-years follow-up. ConclusionsTMS markers of CST dysfunction progress significantly during the pre-ataxic stage of SCA2. SignificanceTMS measures of CST dysfunction may provide biomarkers of disease progression prior to clinical disease expression that have potential utility for monitoring neuroprotective therapies in future clinical trials.

Effectiveness of intraoperative monitoring of motor evoked potentials for predicting changes in the neurological status of patients with cervical spinal cord tumors in the early postoperative period

The study aim was to evaluate the effectiveness of intraoperative monitoring of motor evoked potentials (MEPs) for predicting changes in the neurological status of patients with cervical spinal cord tumors in the early postoperative period. The study included 74 patients with intradural cervical spinal cord tumors who were operated on using motor evoked potential monitoring in the period from 2013 to 2016. There were 29 (39%) males and 46 (61%) females. Group 1 included 26 (35%) patients with intramedullary tumors; group 2 included 48 (65%) patients with intradural extramedullary tumors. The neurological status was assessed by using a six-grade muscle power MRC scale; a modified McCormick scale was used to evaluate the functional status. Transcranial electrical stimulation of the precentral gyri was performed. Recording electrodes were located in the peripheral target muscles of the upper and lower limbs. Total intravenous anesthesia with propofol and fentanyl was used. In Group 1, MEPs decreased in 19 (73%) of 26 patients; MEPs remained unchanged in 7 (27%) patients. Among the patients with decreased MEPs, 14 (74%) patients had postoperative deterioration of the neurological status; 6 (32%) patients had a preoperative severe neurological deficit; 4 (21%) patients had no changes in the neurological status. The sensitivity and specificity of MEPs from the upper limb muscles were higher than those from the lower limb muscles. In Group 2, improvement of the neurological status occurred in all 48 patients. There was no case of a true positive decrease in the MEP amplitude. 1. Registration of MEPs is a highly sensitive and highly specific method for diagnosing corticospinal tract dysfunction in patients with intramedullary tumors of the cervical spinal cord. The sensitivity and specificity of MEPs recorded from the upper limbs are higher than those from the lower limb muscles. 2. The sensitivity of MEPs in patients with extramedullary intradural tumors was 0%, the diagnostic effectiveness of MEPs amounted to 86% from the upper limb muscles and 93% from the lower limb muscles. 3. When the MEP amplitude in patients with extra- and intramedullary tumors of the cervical spinal cord decreases, a change in the surgion's approach may reduce or completely eliminate surgically-induced damage to the spinal cord.

An LMNB1 Duplication Caused Adult-Onset Autosomal Dominant Leukodystrophy in Chinese Family: Clinical Manifestations, Neuroradiology and Genetic Diagnosis.

Autosomal dominant adult-onset demyelinating leukodystrophy (ADLD) is a very rare neurological disorder featured with late onset, slowly progressive central nervous system demyelination. Duplication or over expression of the lamin B1 (LMNB1) gene causes ADLD. In this study, we undertook a comprehensive clinical evaluation and genetic detection for a Chinese family with ADLD. The proband is a 52-year old man manifested with autonomic abnormalities, pyramidal tract dysfunction. MRI brain scan identified bilateral symmetric white matter (WM) hyper-intensities in periventricular and semi-oval WM, cerebral peduncles and middle cerebellar peduncles. The proband has a positive autosomal dominant family history with similar clinical manifestations with a trend of genetic anticipation. In order to understand the genetic cause of the disease in this family, target exome capture based next generation sequencing has been done, but no causative variants or possibly pathogenic variants has been identified. However, Multiplex ligand-dependent probe amplification (MLPA) showed whole duplication of LMNB1 gene which is co-segregated with the disease phenotype in this family. This is the first genetically confirmed LMNB1 associated ADLD pedigree from China.

Lifelong course of Zellweger spectrum disorders: A cohort study

Objective: Zellweger spectrum disorders (ZSD) are a group of genetic metabolic disorders caused by a defect in peroxisome biogenesis due to mutations in one of the PEX genes. Although originally seen as a rapidly lethal pediatric disease, an increasing number of patients with a relatively mild or aspecific phenotype were recognized over the past few years as a result of improved clinical and biochemical characterization. Consequently, a substantial percentage of ZSD patients reach adulthood nowadays. Since only limited data on the natural course of the disease in these relatively mild patients are available, this retrospective cohort study aims to gain insight in the natural course of these patients. Methods: Clinical and laboratory data were collected retrospectively from a large cohort of patients with a genetically confirmed ZSD. All patients were regularly followed up and examined as a part of standard patient care. Results: A total of 22 patients in this ZSD cohort reached adulthood. All patients, except one patient with PEX10 mutations, had vision and hearing impairment. Neurological symptoms comprised pyramidal tract dysfunction, cerebellar syndrome and peripheral neuropathy, in most cases eventually leading to a gait disorder. Two patients suffered from epileptic seizures. In multiple adult patients, a relatively rapid progression of mainly neurological symptoms is described after a long period of stabilization, accompanied by diffuse white matter abnormalities and general cerebral atrophy on MRI- imaging. Conclusion: Most patients with a ZSD at the mild end of the spectrum suffer from slowly progressive neurological symptoms, vision and hearing impairment. Rapid progression of neurological symptoms after a long period of stabilization can occur, whilst biochemical abnormalities have normalized over the years. The exact pathophysiology of this rapid deterioration remains to be elucidated.

Assessment of corticospinal tract dysfunction and disease severity in amyotrophic lateral sclerosis. (P5.076)

Assessment of corticospinal tract dysfunction and disease severity in amyotrophic lateral sclerosis. (P5.076)

Cholesterol Homeostasis and the Pathogenesis of Multiple System Atrophy

Multiple system atrophy (MSA) is a sporadic neurodegenerative disease among adults, which can be characterized by autonomic nerve dysfunction, Parkinsonism, ataxia and pyramidal tract dysfunction, or overlapped symptoms. It can mainly be divided into two types: Parkinsonism (MSA-P) and cerebellum type (MSA-C). The pathology of this disease is the accumulation of alpha-synuclein in oligodendrocyte. And because of this, it belongs to synucleinopathies. Alpha-synuclein is a kind of protein, which has a close connection with lipid membrane in the process of biosynthesis of central nervous system, and this close relationship may play a crucial role in the mechanism of alpha-synucleinopathies. Recently researchers who have focused on the serum lipids level in MSA patients are taking a stab at finding the diagnostic biomarkers, like serum cholesterol level, so as to develop effective therapies in the early stage of MSA. Therefore, the purpose of our review is to summarize the valuable part of recent researches on cholesterol level of MSA patients and to discuss the optimal way to evaluate MSA disease in a simple way to diagnose it early.

Intraoperative Neuromonitoring and Alarm Criteria for Judging MEP Responses to Transcranial Electric Stimulation: The Threshold-Level Method.

The motor evoked potential (MEP) is used in the operating room to gauge-and ultimately protect-the functional integrity of the corticospinal tract (CST). However, there is no consensus as to how to best interpret the MEP for maximizing its sensitivity and specificity to CST compromise. The most common way is to use criteria associated with response magnitude (response amplitude; waveform complexity, etc.). With this approach, should an MEP in response to a fixed stimulus intensity diminish below some predetermined cutoff, suggesting CST dysfunction, then the surgical team is warned. An alternative approach is to examine the minimum stimulus energy-the threshold-needed to elicit a minimal response from a given target muscle. Threshold increases could then be used as an alternative basis for evaluating CST functional integrity. As the original proponent of this Threshold-Level alarm criteria for MEP monitoring during surgery, I have been asked to summarize the basis for this method. In so doing, I have included justification for what might seem to be arbitrary recommendations. Special emphasis is placed on anesthetic considerations because these issues are especially important when weak stimulus intensities are called for. Finally, it is important to emphasize that all the alarm criteria currently in use for interpreting intraoperative MEPs have been shown to be effective for protecting CST axons during surgery. Although differences between approaches are more than academic, overall it is much better for patient welfare to be using some form of MEP monitoring than to use none at all, while you wait for consensus about alarm criteria to emerge.

Corticomuscular Coherence: a Novel Tool to Assess the Pyramidal Tract Dysfunction in Spinocerebellar Ataxia Type 2.

Clinical signs of corticospinal tract dysfunction are a common feature of spinocerebellar ataxia type 2 (SCA2) patients. The objective of this study is to assess dysfunction of the corticospinal tract in SCA2 using corticomuscular coherence. Testing corticomuscular coherence and rating of ataxia severity and non-ataxia symptoms were performed in 19 SCA2 patients and 24 age-matched controls. Central motor conduction times (CMCT) to upper and lower right limbs were obtained for the SCA2 group using Transcraneal magnetic stimulation (TMS). SCA2 patients exhibited a significant reduction of corticomuscular coherence for lower limbs, but not for upper limbs. This difference remained significant, even when excluding those individuals with clinical signs of corticospinal tract dysfunction. Corticomuscular coherence for lower limbs correlated inversely with CMCT to tibialis anterior muscle. Corticomuscular coherence could be a valuable electrophysiological tool to assess the corticospinal tract involvement in SCA2, even in the absence of clinical signs of corticospinal tract dysfunction.

Understanding Multiple System Atrophy—Could Genetics Lead the Way?

Multiple system atrophy (MSA) is a progressive, adult-onset, neurodegenerative disorder characterized by parkinsonism, cerebellar ataxia, autonomic failure, and corticospinal tract dysfunction. It is considered a rare disease, similar in frequency to the more well-known neurodegenerative disease amyotrophic lateral sclerosis or Lou Gehrig’s disease. Though MSA has not traditionally been considered a genetic disease, new evidence is emerging supporting some genetic predisposition in many patients. In this short review, we will discuss advances in the knowledge of genetics in MSA and how this has furthered our understanding of the pathophysiology of the disease. There is still much unknown about this disease, but some of the recent advances made in MSA genetics may give important clues to understanding the pathogenesis and treatment of this disease.

A Newly Identified Missense Mutation in FARS2 Causes Autosomal-Recessive Spastic Paraplegia.

Hereditary spastic paraplegia (HSP) is a clinically and genetically heterogeneous group of neurodegenerative disorders characterized by spasticity of the lower limbs due to pyramidal tract dysfunction. Here, we report that a missense homozygous mutation c.424G>T (p.D142Y) in the FARS2 gene, which encodes a mitochondrial phenylalanyl tRNA synthetase (mtPheRS), causes HSP in a Chinese consanguineous family by using combination of homozygous mapping and whole-exome sequencing. Immunohistochemical experiments were performed showing that the FARS2 protein was highly expressed in the Purkinje cells of rat cerebellum. The aminoacylation activity of mtPheRS was severely disrupted by the p.D142Y substitution in vitro not only in the first aminoacylation step but also in the last transfer step. Taken together, our results indicate that a missense mutation in FARS2 contributes to HSP, which has the clinical significance of the regulation of tRNA synthetases in human neurodegenerative diseases.

Prevalence of motor abnormalities among healthy 5-year-old children

The prevalence of motor examination abnormalities among a general pediatric population is unknown. We determined the frequency of motor abnormalities noted at five years of age during a neurologic examination by a child neurologist. As part of a follow-up study of neonatal jaundice in a population of 106,627 births, we randomly selected 419 five-year-old children as healthy controls, of whom 168 consented. Child neurologists blinded to the children’s history performed standard neurologic examinations to determine the presence of definite or subtle motor abnormalities. Standardized data on motor and cognitive function were also obtained. Among eight (5%) children diagnosed with a definite motor abnormality, the most common finding was corticospinal tract dysfunction (four unilateral, two bilateral). Two children demonstrated hypotonia and hyporeflexia, one of whom also exhibited proximal weakness. An additional 12 (7%) children were noted to have subtle motor findings that were not clearly abnormal, such as subtle incoordination, mild dystonic posturing, tremor, posting, or hyperreflexia. Children with definite or subtle motor findings were more likely to receive an abnormal score on the Motor Performance Checklist (57% vs. 32%, P = 0.02). There was also a trend towards these children having a lower mean verbal IQ compared to children with normal motor examinations (95.3 vs. 102.1, P = 0.07). Motor examination abnormalities in otherwise healthy 5-year-old children may be more common than previously thought. However, the proportion of children with motor examination abnormalities who have an unrecognized neurologic disorder remains unknown.

3-A-D-2-5. Prolonged central conduction time in a patient with Guillain–Barre syndrome presenting Babinski’s sign

A 44-year-old Japanese woman was referred to our hospital complaining of progressive weakness of limbs over the prior 2 days. A neurological examination showed oculomotor disturbance, bilateral facial nerve palsy, dysarthria, dysphagia, limb muscle weakness, diminished deep tendon reflexes, bilateral positive Babinski’s sign, sensory disturbance in limbs and bladder or bowel dysfunction. Nerve conduction studies revealed decreased F-wave frequencies in median and ulnar nerves. The motor evoked potential (MEP) induced in the abductor pollicis brevis muscle (APB) showed prolonged latency (26.9 ms), and the calculated central motor conduction time (CMCT) was delayed at 13.6 ms. A cerebrospinal fluid analysis revealed elevated protein level (103 mg/dL) and mild pleocytosis (8/μL). Antiganglioside antibodies were positive for GM1, GD1b, GD3, GT1b, GQ1b, and GT1a. Brain and spinal MRI showed no abnormal findings. She was treated with high-dose intravenous immunoglobulin, and on the 19th day of her illness, the Babinski’s sign had disappeared. Post-treatment, the MEP latency and CMCT in the APB were improved at 20.5 and 7.9 ms, respectively. This case suggests that patients with Guillain–Barre syndrome can present Babinski’s sign as a result of pyramidal tract dysfunction caused by antiganglioside antibodies.

Superficial siderosis of the central nervous system: A case report.

Superficial siderosis of the central nervous system (SSCNS) is a rare syndrome resulting from hemosiderin deposits in neuronal tissues close to the cerebrospinal fluid. SSCNS is characterized by sensorineural deafness, cerebellar ataxia and signs of pyramidal tract dysfunction. The present study describes a patient with SSCNS that did not suffer from hearing loss, which is the most common symptom of SSCNS. The patient was a 48-year-old male, presenting with dizziness, ataxia and slurred speech. The patient’s ataxia was characterized by dizziness, nystagmus, dysarthria, abnormal finger-nose pointing and heel-knee-shin tests and a positive Chaddock sign. The patient had suffered from a pontine hemorrhage two years prior to the study. Audiometric tests showed normal hearing during the hospital stay and at the two-month follow-up examination. The diagnosis of SSCNS was made based on magnetic resonance images, which showed areas of linear hypointensity on the surface of the pons with mild cerebellar atrophy. However, a long-term follow-up is required to monitor the hearing of the patient. Improved understanding of SSCNS is important for clinicians to identify SSCNS patients who present without typical clinical symptoms.

Accuracy of the Babinski sign in the identification of pyramidal tract dysfunction

BackgroundThe extensor plantar response described by Joseph Babinski (1896) indicates pyramidal tract dysfunction (PTD) but has significant inter-observer variability and inconsistent accuracy. The goal of this study was to determine the accuracy of the Babinski sign in subjects with verified PTD. MethodsWe studied 107 adult hospitalized and outpatient subjects evaluated by neurology. The reference standard was the blinded and independent diagnosis of an expert neurologist based on anamnesis, physical examination, imaging and complementary tests. Two neurologists elicited the Babinski sign in each patient independently, blindly and in a standardized manner to measure inter-observer variability; each examination was filmed to quantify intra-observer variability. ResultsCompared with the reference standard, the Babinski sign had low sensitivity (50.8%, 95%CI 41.5–60.1) but high specificity (99%, 95%CI 97.7–100) in identifying PTD with a positive likelihood ratio of 51.8 (95%CI 16.6–161.2) and a calculated inter-observer variability of 0.73 (95%CI 0.598–0.858). The intraevaluator reliability was 0.571 (95%CI 0.270–0.873) and 0.467 (95%, CI 0.019–0.914) respectively, for each examiner. ConclusionThe presence of the Babinski sign obtained by a neurologist provides valid and reliable evidence of PTD; due to its low sensitivity, absence of the Babinski sign still requires additional patient evaluation if PTD is suspected.

Tic Disorder Probably Associated with Steroid Responsive Encephalopathy with Autoimmune Thyroiditis (SREAT)

Steroid responsive encephalopathy with autoimmune thyroiditis (SREAT), a rare disorder in individuals of all age groups, including children, is characterized by high titers of anti-thyroid peroxidase antibodies. The present report concerns a previously healthy 12-y-old boy who presented with motor tics. The patient underwent an extensive work-up to identify the underlying etiologies and risk factors predisposing him to tic disorder. Based on the clinical and laboratory results, a diagnosis of SREAT was made. Although some studies have reported associated behavioral and cognitive changes, myoclonus, seizures, pyramidal tract dysfunction, psychosis, and coma. The authors describe a case of tic disorder, probably due to SREAT, as well as its course of treatment.

KIF1C mutations in two families with hereditary spastic paraparesis and cerebellar dysfunction

BackgroundHereditary spastic paraparesis (HSP) (syn. Hereditary spastic paraplegia, SPG) are a group of genetic disorders characterised by spasticity of the lower limbs due to pyramidal tract dysfunction. Nearly 60 disease...

Enhanced reticulospinal output in patients with (REEP1) hereditary spastic paraplegia type 31

Dear Sirs, The striking paradox of pure autosomal dominant hereditary spastic paraplegia (AD HSP), in contrast to capsular stroke or primary lateral sclerosis, for example, is that despite extensive corticospinal tract (CST) degeneration and prominent lower limb spasticity, leg weakness is not a prominent early feature of the disease. Therefore, other descending motor pathways presumably compensate for CST degeneration, though, until the recent article by Nonnekes et al. [1] in the Journal of Neurology, this assumption had remained unproven. Using startling acoustic stimuli (SAS), they showed that the reticulospinal tract (RST) is not only functioning in patients with HSP, but that it compensates for lower limb deficits of postural control caused by CST degeneration. In most patients with pure AD HSP, electrophysiological evidence of CST disease is limited to the lumbosacral cord [2]. However, some AD HSP genotypes (e.g., SPG4) are associated with a more severe phenotype and have motor-evoked potential (MEP) abnormalities in the upper limbs [3–5], consistent with post-mortem evidence of CST degeneration at all levels, from the medulla to the lumbo-sacral cord [6]. We tested MEPs (see Supplementary Methods) in two patients (father and son) with SPG31 AD HSP (REEP1 exon 5 c.337C > T/p.Arg113X [7]). In patient 2 (age 42; disease duration 37 years) MEPs were ‘typical’ of pure AD HSP [8], with prolonged central motor conduction times (CMCTs) in the lower limbs (CMCT 22.2 ms) and normal CMCTs in the upper limbs. However, in patient 1 (age 68; disease duration 64 years) CMCTs were significantly prolonged in the upper limbs (Fig. 1). Fig. 1 Examples of rectified motor-evoked potentials (MEPs) obtained from a 68-year-old patient with SPG31/REEP1 HSP (black) and an age-matched control (grey), aligned to the stimulus. a Upper limb MEPs recorded from right first dorsal interosseous (R FDI) and ... Given the absence of clinical upper limb weakness in patient 1, we measured EMG onset latencies in a Start-React paradigm to see whether the RST might be compensating for the CST deficit in the upper limbs [9–11] (Supplementary Methods), as illustrated in Fig. 2a. Experiments had the relevant institutional ethical approval and complied with the Declaration of Helsinki, and were performed in both patients and 11 controls, aged 56–82 years. Traditionally, the effects of SAS on the visual reaction time (VRT), and the visual start-react time (VSRT), are normalized, thus: 1 Fig. 2 a Example of normal raw rectified EMG data recorded from right biceps brachii in a 61-year-old male control subject performing the Start-React task. The EMG burst from which the VRT was measured is plotted in black, that from which the ART was derived ... The normal ∆VRT is ~50 % [9], and a ∆VRT of less than 50 % is indicative of disease affecting the RST. However, because we were interested in measuring any change in the gain of the RST output, accessed via auditory pathways, we have used a ratio that incorporates the auditory reaction time (ART) following a low-intensity sound, as follows: 2 where ∆TSR is the shortening effect of a SAS on the visual reaction time and ∆TAR measures the shortening of reaction time provided by a non-startling auditory stimulus, which presumably does not activate RST pathways. The results of this analysis are shown in Fig. 2c, d. Patient 2, who had no evidence of cervical CST disease, had normal ∆TSR/∆TAR ratios. However, patient 1, who had MEP evidence of cervical CST disease, had significantly increased ratios, but only when measured from biceps brachii EMG, despite normal ARTs and VRTs (Supplementary Results/Fig. 2). This result supports the notion that the RST mitigates the effects of disease within the cervical CST. The RST appears to compensate by increasing its output gain by a factor of around 1.5. Although the RST does project to both proximal and distal upper limb muscles [12], the effects of SAS are only seen in distal muscles in some tasks [13], possibly explaining why we detected differences only in the biceps muscle. These observations suggest that therapeutic interventions aimed at increasing the gain of RST outputs could improve recovery from neurological disorders characterized by CST dysfunction.

Lamin B1 mediates cell-autonomous neuropathology in a leukodystrophy mouse model.

Adult-onset autosomal-dominant leukodystrophy (ADLD) is a progressive and fatal neurological disorder characterized by early autonomic dysfunction, cognitive impairment, pyramidal tract and cerebellar dysfunction, and white matter loss in the central nervous system. ADLD is caused by duplication of the LMNB1 gene, which results in increased lamin B1 transcripts and protein expression. How duplication of LMNB1 leads to myelin defects is unknown. To address this question, we developed a mouse model of ADLD that overexpresses lamin B1. These mice exhibited cognitive impairment and epilepsy, followed by age-dependent motor deficits. Selective overexpression of lamin B1 in oligodendrocytes also resulted in marked motor deficits and myelin defects, suggesting these deficits are cell autonomous. Proteomic and genome-wide transcriptome studies indicated that lamin B1 overexpression is associated with downregulation of proteolipid protein, a highly abundant myelin sheath component that was previously linked to another myelin-related disorder, Pelizaeus-Merzbacher disease. Furthermore, we found that lamin B1 overexpression leads to reduced occupancy of Yin Yang 1 transcription factor at the promoter region of proteolipid protein. These studies identify a mechanism by which lamin B1 overexpression mediates oligodendrocyte cell-autonomous neuropathology in ADLD and implicate lamin B1 as an important regulator of myelin formation and maintenance during aging.

Tectal plate gliomas: a review

Tectal plate gliomas are generally benign neoplastic lesions arising in the brainstem which can, with local extension, obstruct the aqueduct of Sylvius and lead to hydrocephalus. Diagnosis is based on initial suspicion fostered by the presentation of an obstructive hydrocephalus followed by physical exam which may potentially reveal indications of pyramidal tract dysfunction or cranial nerve palsies. MRI studies reveal a characteristic well-circumscribed, isodense or hypodense mass on T1-weighted images, with hyperdensity on T2 imaging. Yet current radiological methods insufficiently distinguish tectal plate gliomas from brainstem tumors or gliomas in the neighboring structures, and a definitive diagnosis requires biopsy and histopathological analysis. Management is planned according to the degree of associated signs and symptoms, and may range from diligent observation and periodic screening for advancing tumor development, to cerebrospinal fluid shunting in an effort to resolve obstructive hydrocephalus, to radio- and chemotherapy. A wide range of minimally invasive approaches using endoscopy is available for the neurosurgeon, including endoscopic third ventriculostomy and endoscopic aqueductoplasty.