Correlation of Pattern Reversal and Flash Visual Evoked Potential Latencies With Optical Coherence Tomography Measures in Patients With Optic Neuropathy and Patients With Multiple Sclerosis Without Optic Neuropathy.

PURPOSE: The object of the study is to relate the pattern reversal visual evoked potential (PRVEP) and flash VEP (f-VEP) latencies with retinal neurons and their fibers. METHODS: We studied 104 eyes. Forty-two eyes from patients with optic neuritis (ON), 28 eyes from patients with multiple sclerosis without involvement of the optic nerves (MS-non-ON), and 34 eyes of normal controls. RESULTS: Pattern reversal visual evoked potential latency is more delayed in patients with ON than in patients with multiple sclerosis nonON. Flash visual evoked potential (f-VEP) latency was delayed in both categories. Peripapillary retinal nerve fiber layer (pRNFL) and ganglion cell/inner plexiform layer (GCIPL) thickness was lower in patients with ON and multiple sclerosis non-ON. In patients with ON, f-VEP latencies correlated negatively with pRNFL thickness but not GCIPL thickness. In patients with ON, PRVEP latencies did not correlate with pRNFL thickness but correlate negatively with GCIPL thickness. CONCLUSIONS: Patients with ON have delayed VEPs and thinner optical coherence tomography values. Flash visual evoked potentials correlate with pRNFL, indicating axonal pathology. PRVEP correlate with GCIPL, indicating ganglion cell pathology. Abnormal PRVEP with preserved normal f-VEP indicate isolated myelin damage. Abnormalities in both PRVEP and f-VEP indicate myelin and axonal damage in the optic nerve. Combining the results of PRVEP, f-VEP, pRNFL, and GCIPL, one can define the location, type, and extent of the lesion in the macula and optic nerve.

Rituximab Treatment for Chronic Idiopathic Axonal Polyneuropathy.

ABSTRACT: Chronic idiopathic axonal polyneuropathy is a disorder of unknown etiology resulting in progressive weakness and sensory disturbances predominantly in the hands and feet. Nerve conduction studies and electromyography confirm axonal damage in the nerves of the upper and lower extremities. The pathology is symmetrical with a distal predilection. Patients usually do not respond to the classical treatment with steroids, intravenous immunoglobulin, plasmapheresis, or immunosuppressant drugs. We describe 2 cases of chronic idiopathic axonal polyneuropathy who received intravenous rituximab as a last resort because of the severity of their symptoms. Both patients showed dramatic improvement in their weakness, muscle atrophy, numbness, and paresthesias only few weeks after the induction dose. Their daily functional activities improved to self-independence.

Auricular Myoclonus: A Case Report and Literature Review.

Auricular myoclonus is an extremely rare disorder that manifests as involuntary semi-rhythmic movements of the auricle. We report the case of a 15-year-old female who presented to our outpatient clinics with bilateral spontaneous, uncontrolled movements of the auricles (auricular myoclonus) that are only briefly suppressible by some facial movements and completely disappear during sleep. Needle electromyography revealed baseline tonic motor unit activity with bursts of higher motor units amplitude in the posterior and superior auricularis muscles. Her symptoms improved with pregabalin intake, however, with incomplete resolution. This paper will review previously reported cases, as well as the different treatment modalities that have been used.

Posterior Tibial Nerve Lymphoma Presenting as Tarsal Tunnel Syndrome: A Case Report.

We report a case of isolated posterior tibial B-cell lymphoma of the posterior tibial nerve presenting as tarsal tunnel syndrome. This diagnosis was considered because of the clinical presentation and electrophysiologic abnormalities. It was further confirmed by the magnetic resonance imaging findings of the ankle and tissue pathologic findings. Whole body positron emission tomography confirmed this to be a localized lymphoma involving the peripheral nerve. The patient underwent chemotherapy with complete tumor resolution. She had had no relapse after 8 months of follow-up. Isolated peripheral nerve lymphomas are very rare, and involvement of the posterior tibial nerve has not been previously reported. Furthermore, the present case report highlights the importance of the clinical examination in the diagnosis of tarsal tunnel syndrome before performing surgical decompression.

Safety and efficacy of reduced fingolimod dosage treatment.

BACKGROUND: Oral fingolimod is a sphingosine-1-phosphate-receptor modulator that prevents the egress of lymphocytes from lymph nodes. Fingolimod reduces relapse rate and delays disability progression in patients with relapsing forms of multiple sclerosis (MS). Elevation of liver function tests (LFTs) and reduction in peripheral-blood lymphocyte counts were among the most common adverse events reported in phase II, phase III, and extension studies. OBJECTIVE: To describe eight patients in whom fingolimod dose was reduced to every other day (n=6) or every third day (n=2) due to increased LFTs more than 3 times the upper limit of normal (ULN) (n=2) or decreased lymphocyte count by ≤0.2×10(9)/L (n=6). RESULTS: Fingolimod dose reduction resulted in reversal of laboratory abnormalities. Clinically, none of the 8 patients developed clinical relapses, but five patients had new lesions on magnetic resonance imaging (MRI), one of whom with disability progression, and one patient converted to secondary progressive MS (SPMS). CONCLUSION: Reducing the frequency of fingolimod administration can reverse laboratory abnormalities but may have a negative impact on drug efficacy.

Gene mutations and stroke in the young adult.

BACKGROUND: The purpose of this study is to evaluate the existence of the genetic mutation in the different types of cerebral and spinal strokes in previously healthy young adults. METHODS: We performed a retrospective study of the medical records of 35 young adults who presented to our institution with the diagnosis of acute cerebrovascular insult. We defined the localization of their stroke, specified their risk factors, defined their genetic mutation, and correlated these variables to assess their significance in the predisposition of stroke in the young. RESULTS: We found that the MTHFR and Factor V gene mutations are the most likely mutations to be associated with cerebral strokes in young adults. Spinal strokes are also associated with beta fibrinogen, factor XIII, and prothrombin II mutations. We did not find that a homozygous gene mutation is more thrombogenic than its heterozygous component. CONCLUSIONS: We concluded that the major etiologies for stroke in young adults were multiple gene mutations rather than systemic illnesses. We found out that mutation of the MTHFR gene in isolation or in combination with other gene mutations is the most important risk factor for stroke in the young.

Toxocara canis myelitis: clinical features, magnetic resonance imaging (MRI) findings, and treatment outcome in 17 patients.

Toxocara myelitis is a rare disease. Few cases have been reported in the literature. Patients present with myelopathy, occasional eosinophilia in blood and cerebrospinal fluid (CSF), with abnormal signals on magnetic resonance imaging (MRI). In the current study we report 17 cases of isolated Toxocara myelitis from a single tertiary referral center in Lebanon, with description of the clinical presentation, laboratory data, MRI findings, and response to antihelminthic treatment. Clinical and laboratory data were collected for 17 patients who presented with evidence of spinal cord disease. The clinical presentation included sensory, motor, and autonomic dysfunction, predominantly in the lower extremities. Patients exhibited a subacute or chronic course; this was either slowly progressive or remitting-relapsing with mild to moderate disability. The patients underwent extensive blood and CSF workup as well as MRI of the spinal cord and brain. Only 2 patients had a high eosinophil count in the CSF, although blood eosinophilia was seen in 6 patients. All patients tested positive for Toxocara canis antibodies in the blood and CSF. MRI of the spinal cord revealed a single characteristic lesion in the spinal cord with fusiform enlargement that was isointense on T1-weighted images and hyperintense on T2-weighted images. Nodular enhancement was seen after gadolinium injection. Treatment with albendazole, with or without steroids, resulted in marked neurologic improvement and normalization of the MRI in all patients.The finding of a single inflammatory MRI lesion in the spinal cord with positive Toxocara canis serology in the blood and CSF in cases of subacute or chronic myelitis suggests the diagnosis of Toxocara myelitis, irrespective of the presence of eosinophilia. Antihelminthic treatment is associated with a good outcome.

Morvan syndrome following B-cell lymphoma.

Morvan syndrome is a rare autoimmune disease named after the French physician Augustin Marie Morvan. It is characterized by multiple, irregular contractions of the long muscles, weakness, pruritus, hyperhidrosis, insomnia, and delirium. Here, we describe a 17-year-old young man, previously diagnosed with B-cell lymphoma, who presented with multiple asynchronous fasciculations of the long muscles of his lower extremities accompanied by numbness. The patient responded initially to pulse corticosteroids with diminution of the fasciculations. He achieved complete remission following 7 consecutive, monthly intravenous immunoglobulin injections. The present case is described in the context of the available literature.

Use of recombinant activated factor VII for intractable bleeding in patients without hemophilia: A developing country tertiary care center's experience.

Although the use of recombinant activated factor VII (rFVIIa) to control intractable bleeding in nonhemophiliac patients is expanding, several issues pertinent to its potential thrombotic complications and effect on patient mortality are still of concern. We herein describe our experience at a developing country tertiary care center over a period of 4 years. A total of 49 patients were identified of whom 28.6% belong to the pediatric age group. The most common bleeding settings were intracerebral hemorrhage, abdominal aortic surgery, general surgery, and disseminated intravascular coagulopathy. All patients achieved cessation or significant reduction in bleeding. Only 1 patient had a documented postuse thrombotic complication. Of the whole group, 12 patients (24.4%) eventually died with only 1 death having a possible association to rFVIIa use. There was a statistically significant reduction in the need for blood product transfusion after the use of rFVIIa. The use of rFVIIa was in accordance with the hospital's algorithm (identifying salvageable patients, preconditioning, blood product replacement, and dosing) in 30 (61.2%) patients. We conclude that rFVIIa should continue to be considered in nonhemophiliac patients failing to respond to conventional measures of bleeding control. However, this off-label use should be coupled with strict adherence to the treatment algorithms, which remains essential in developing countries with limited health care resources.

When is the Phalen's test of diagnostic value: an electrophysiologic analysis?

The authors performed nerve conduction studies on 54 hands in patients referred with the clinical diagnosis of carpal tunnel syndrome. The authors studied the motor and sensory latencies of the median and ulnar nerves and compared them with each other. The authors divided the results into hands with no, mild, moderate, or severe carpal tunnel syndrome. The authors correlated these results with the presences or absence of the Phalen's sign. The authors concluded that the Phalen's sign is present mostly in the moderate to severe median nerve entrapment, but still can sometimes be present as a false positivity in normal hands.

Bilateral transverse sinus thrombosis secondary to a homozygous C677T MTHFR gene mutation.

We describe the case of a previously healthy young man who presented with headache, diplopia, nausea, vomiting, and bilateral papilledema. Magnetic resonance venography of the brain revealed thrombosis of the right transverse sinus. Blood tests showed elevated homocysteine levels, and coagulation studies revealed a homozygous C677T mutation and a heterozygous A1298C mutation of the methylenetetrahydrofolate reductase (MTHFR) gene. The patient had no other etiology for venous thrombosis. We recommend screening patients who present with sinus thrombosis for MTHFR gene mutations.

Presumed bilateral optic nerve sheath meningiomas presenting as optic neuritis.

A 30-year-old man who developed acute blurred vision in the right eye and right periocular pain on eye movement proved to have a bilateral optic neuropathy and imaging evidence suggestive of bilateral optic nerve sheath meningiomas. This is an unusual presentation for optic nerve meningioma but a reminder that this entity may mimic optic neuritis.

Contrast-induced encephalopathy following coronary angioplasty with iohexol.

We report a case of a patient who developed acute encephalopathy following coronary angioplasty with iohexol contrast. The patient's clinical condition was associated with slowing on the EEG. Studies did not reveal any other etiology or contributing cause for the encephalopathy. The patient recovered spontaneously in 24 hours with only supportive measures. This report suggests that such a drug reaction could occur with iohexol injected in the coronaries, but reassures that the encephalopathy is self limiting.

Peripheral neuropathy in thalassaemia.

BACKGROUND: Patients with thalassemia may complain of numbness and weakness of the lower extremities. The aim of the study was to document whether these patients suffer from a polyneuropathy and to determine any contributing factors for the development of neuropathy. PATIENTS AND METHODS: We examined 30 patients with thalassemia major and intermedia, clinically and electrophysiologically. We correlated these findings with demographics, blood status, and treatment and compared electrophysiologic data with 30 age- and sex-matched normal subjects or historical controls. RESULTS: We found that 78% of thalassemic patients suffered from a mild sensory polyneuropathy. The neuropathy seemed to be worse in the intermedia type. Thalassemic patients who received blood transfusions and deferoxamine had better nerve function than those who did not, irrespective of the dose of deferoxamine. The neuropathy was worse for older patients, irrespective of sex. The hemoglobin level, and the fact that some patients underwent splenectomy, did not affect the status of the patients' nerves. CONCLUSION: Patients with thalassemia may suffer from a sensory polyneuropathy especially as they grow older and if they are not optimally treated.

Should we screen patients for inherited thrombophilia before starting thalidomide?

The authors present a case of refractory multiple myeloma in an elderly patient with heterozygosity for the G20210A mutation of factor II and for the C677T mutation of methylenetetrahydrofolate reductase. This patient developed acute, multiple cerebral infarctions 5 months into the treatment with thalidomide. The patient improved on oral anticoagulation. The authors presume that thalidomide increased the risk of cerebral infarction in this predisposed patient. The presence of increased risk for thrombosis should alert clinicians to screen patients presenting with systemic thrombosis for inherited thrombophilia. This risk increases with the presence of diseases and therapies that predispose for a hypercoagulable state. They suggest that patients required to be on thalidomide should be screened for inherited thrombophilia and should be considered for prophylactic anticoagulation therapy.

Acute progressive bilateral carpal tunnel syndrome after upper respiratory tract infection.

This report describes the case of a 32-year-old male presenting with acute progressive bilateral carpal tunnel syndrome after a benign upper respiratory tract infection. Serial nerve conduction studies confirmed progressive entrapment of the median nerves in the carpal tunnel to the point of axonal damage. Surgical decompression relieved the entrapment, and nerve conduction studies improved.

Hypertriglyceridemia and peripheral neuropathy in neurologically asymptomatic patients.

OBJECTIVES: In this study we intended to find a correlation between hypertriglyceridemia and peripheral neuropathy (PN) in patients with a high triglyceride level and no neurological complaints. METHODS: We recruited 24 patients (21 males and 3 females) having a triglyceride level above 300 mg/dl with no neurologic complaints and none of the other common causes of PN and they underwent an electroneurographic study. The distal motor or sensory latencies (DL), motor or sensory conduction velocities (CV), and motor or sensory amplitudes (AMP) were collected for the peroneal, posterior tibial, sural, median, and ulnar nerves and were considered abnormal if they fall above or below 2 standard deviations of reference values. RESULTS: Our results show that 70.8% of the patients had a significant delay in the DL of the sural nerves and 66.7% had a significant delay in the DL of the median sensory fibers. 54.2% of the patients had a significant decrease in the motor CV in the posterior tibial nerves and 33.3% had a significant decrease in the sensory CV in the sural nerves. The means of the DL and CV were significantly different from reference values in most of the nerves. Amplitudes were the least if at all affected. CONCLUSION: The pattern of the abnormalities affecting more the DL, the sensory nerves and the longer nerves of the lower extremities is suggestive of an early axonal polyneuropathy. We conclude that hypertriglyceridemia affects conduction parameters in peripheral nerves in a trend suggestive of early peripheral neuropathy.