Alon Abraham

Influence of serum uric acid levels on prognosis and survival in amyotrophic lateral sclerosis: a meta-analysis

Uric acid (UA) is considered to be one of the most important antioxidants in the blood. While high UA levels are found in many disease states, low UA levels are reported in many neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, and amyotrophic lateral sclerosis (ALS). Various studies showed consistently that ALS patients have lower serum UA levels than healthy individuals, more prominently in cases with bulbar onset and longer disease duration. A systematic search of PubMed was conducted to retrieve published studies on UA levels in ALS patients. A meta-analysis was performed on published studies comparing UA levels between ALS patients and controls. This meta-analysis revealed highly statistically significant (pxa0<xa00.0001) lower UA levels and a very large size effect in 311 ALS patients compared to 515 controls as a group, as well as calculated for men and women separately. Many studies indicate that patients with neurodegenerative diseases, including ALS, have low UA levels. Our meta-analysis strengthens these findings in ALS patients, demonstrating highly statistically significant (pxa0<xa00.0001) lower UA levels in patients compared to controls, with very large total size effect, more prominent in men.

Fatigue in motor neuron diseases

Motor neuron diseases as amyotrophic lateral sclerosis and post-polio syndrome are characterized by prominent muscular weakness and severe motor disability. The prevalence of fatigue in motor neuron diseases is remarkably high, and may contribute significantly to patients disability and a poor quality of life. Despite its high prevalence, fatigue is an understudied clinical problem in motor neuron diseases and is often overlooked. The present review will attempt to explain the pathogenic mechanisms of muscle fatigue in amyotrophic lateral sclerosis and post-polio syndrome, to cover the various methods of quantification of fatigue that measure both subjective and physiological components, and to summarize the evidence regarding therapeutic interventions that can be used in order to minimize this symptom.

Laser Doppler Flare Imaging and Quantitative Thermal Thresholds Testing Performance in Small and Mixed Fiber Neuropathies

Introduction Small fiber neuropathy might be a part of typical mixed small and large fiber neuropathy, or a distinct entity, affecting exclusively small nerve fibers. Objectives Explore the utility of small nerve fiber testing in patients with clinical presentation suggesting small fiber neuropathy, with and without evidence for concomitant large fiber neuropathy. Methods Patients attending the neuromuscular clinic from 2012 to 2015 with a clinical presentation suggesting small nerve fiber impairment, who had Laser Doppler flare imaging (LDIFlare) and quantitative thermal testing (QTT) were evaluated for this study. Patients with clinical or electrophysiological evidence for concomitant large fiber neuropathy were not excluded. Results The sensitivities of LDIFlare, cooling and heat threshold testing were 64%, 36%, and 0% respectively for clinically highly suggestive small fiber neuropathy, 64%, 56%, and 19% respectively for mixed fiber neuropathy, and 86%, 79%, and 29% respectively for diabetic mixed fiber neuropathy. Discussion LDIFlare and cooling thresholds testing are non-invasive small nerve fiber testing modalities, with moderate performance in patients with small and mixed fiber neuropathy, and excellent performance in diabetic mixed fiber neuropathy.

Posterior reversible encephalopathy syndrome resulting from Guillain-Barré-like syndrome secondary to West Nile virus infection.

A 67-year-old woman developed hypertension, drowsiness, hemianopia, ascending flaccid tetraparesis, and areflexia. Nerve conduction studies revealed a demyelinating polyneuropathy. Brain magnetic resonance imaging demonstrated hyperintense white matter lesions. IgM antibodies against West Nile virus were positive. She was treated for hypertension and with intravenous immunoglobulins and recovered completely within 2 months. To our knowledge, this is the first case in which West Nile virus infection presented as posterior reversible encephalopathy syndrome associated with Guillain-Barré-like syndrome.

Effect of neck flexion on somatosensory and motor evoked potentials in Hirayama disease

UNLABELLEDnHirayama disease (HD) is a rare motor disorder mainly affecting young men, characterized by atrophy and weakness of forearm and hand muscles corresponding to a C7-T1 myotome distribution. The weakness is usually unilateral or asymmetric and progression usually stops within several years. The etiology of HD is not well understood. One hypothesis, mainly based on MRI findings, is that the weakness is a consequence of cervical flexion myelopathy. The aim of this study was to explore the function of corticospinal and ascending somatosensory pathways during neck flexion using evoked responses.nnnMATERIALS AND METHODSn15 men with HD and 7 age-matched control male subjects underwent somatosensory evoked potentials (SSEP) and motor evoked potentials (MEP) studies with the neck in neutral position and fully flexed. SSEP studies included electrical stimulation of median and ulnar nerves at the wrist, and tibial nerve at the ankle with recording over the ipsilateral Erbs point, cervical spine, and contralateral sensory cortex. MEP recordings were obtained by magnetic stimulation of the motor cortex and the cervical lower spinal roots; the evoked responses were recorded from the contralateral thenar and abductor hallucis muscles.nnnRESULTSnMEP recordings demonstrated significant lower amplitudes, and slightly prolonged latencies in HD patients on cervical stimulation, compared to control subjects. During neck flexion, MEP studies also demonstrated a statistically significant drop in mean upper limb amplitude on cervical stimulation in HD patients, as well as in control subjects, although to a lesser degree. In contrast, no significant differences were found in SSEP studies in HD patients compared to control subjects, or between neutral and flexed position in these groups.nnnCONCLUSIONnThe study shows a negative effect of cervical flexion on MEP amplitudes in HD patients as well as in control subjects, requiring more studies to investigate its significance. Neck flexion did not have an influence on any SSEP parameters in patients or controls.

Peripheral nerve ultrasound imaging shows enlargement of peripheral nerves outside the brachial plexus in neuralgic amyotrophy.

Purpose: Neuralgic amyotrophy is characterized by acute or subacute onset of shoulder and arm pain, followed by muscle atrophy and weakness, and variable sensory abnormalities. Historically, the site of inflammation has been localized to the brachial plexus, although the involvement of individual nerve branches has been well recognized. Methods: We describe ultrasound findings in two cases with a clinical presentation suggestive of neuralgic amyotrophy, involving individual peripheral nerves, correlating with clinical and electrophysiological findings. Results: In the first case, selective fusiform enlargement of the left radial nerve in the proximal forearm is shown, whereas in the second case, fusiform enlargement of the left median nerve in the antecubital fossa is shown. Discussion: These cases confirm that the site of nerve inflammation may lie outside the brachial plexus, keeping with previous reports, and suggests that peripheral nerve ultrasound imaging might aid in the diagnosis of neuralgic amyotrophy and exclude mimicking conditions.

Nocturnal carbon dioxide monitoring in patients with idiopathic intracranial hypertension.

BACKGROUNDnIdiopathic intracranial hypertension may be associated with sleep apnea. This study evaluated the incidence of sleep breathing disorders in patients with idiopathic intracranial hypertension.nnnMATERIALS AND METHODSnOvernight respiratory monitoring was performed in 22 untreated patients with idiopathic intracranial pressure diagnosed at a tertiary medical center over a two-year period and 12 sex- and age-matched control subjects. Breathing measures included heart rate, respiratory rate,oxygen saturation, and continuous end-tidal capnography. Sleep quality and daily fatigue were assessed by self-report questionnaires.nnnRESULTSnMean age of the study group was 32.6±12.2 years and of the control group, 37.0±12.9 years. Neither group had significant findings of hypoxia or hypercarbia during sleep, and there were no between-group differences in mean carbon dioxide level (patients, 35.8±4.41 mmHg; controls, 37.6±4.38 mmHg; p>0.02) or minimal oxygen saturation (96.35±1.99% and 5.69±1.71%, respectively; p>0.02). The study group had significantly more events of apnea (CO2) per hour of sleep than the control group (1.21±1.38 and 0.92±0.56, respectively; p=0.02), although values were still within normal range (<5/hr).nnnCONCLUSIONnIdiopathic intracranial hypertension is not associated with a clinically significant nocturnal breathing abnormality, and hypercarbia is apparently not involved in the pathogenesis. However, it is possible that a subtle increase in paroxysmal sleep apnea (CO2) events might be sufficient to cause vasodilatation of the cerebral blood vessels, thereby increasing intracranial pressure. Screening for sleep apnea may be appropriate in idiopathic intracranial hypertension patients, and further studies are needed to clarify this issue.

Listening to music during electromyography does not influence the examinee's anxiety and pain levels.

Introduction: Listening to music is a low‐cost intervention that has demonstrated ability to reduce pain and anxiety levels in various medical procedures. Methods: Subjects undergoing electrophysiological examinations were randomized into a music‐listening group and a control group. Visual analog scales were used to measure anxiety and pain levels during the procedure. Results: Thirty subjects were randomized to each group. No statistically significant difference was found in anxiety or pain levels during the procedure between groups. However, most subjects in the music‐listening group reported anxiety and pain reduction and would prefer to hear music in a future examination. Conclusions: Although listening to music during electrophysiological examinations did not reduce anxiety or pain significantly, most subjects felt a positive effect and would prefer to hear music; therefore, we suggest that music may be offered optionally in the electromyography laboratory setting. Muscle Nerve 50: 445–447, 2014

Dynamic MRI testing of the cervical spine has prognostic significance in patients with progressive upper-limb distal weakness and atrophy

BACKGROUNDnThe syndrome of isolated progressive upper-limb distal weakness and atrophy results from disease processes affecting lower motor neurons originating in the cervical anterior horn gray matter. Lower motor neuron dysfunction restricted to the C7-T1 myotomes in the absence of neuropathy, upper motor neuron signs, sphincter disturbances or abnormality on conventional MR imaging is suggestive of either Hirayama disease (HD), or the initial manifestation of a progressive motor neuron disease such as amyotrophic lateral sclerosis (ALS). In HD the supposed etiologic mechanism is a mechanical compression of the cervical spinal cord during neck flexion; therefore, dynamic MRI (dMRI) of the cervical cord might help differentiate between these possibilities.nnnMETHODSnThis was a multi-center observational cohort study. Over a 4-year period between 8/2009 and 8/2013, 22 patients were identified as having a disease consistent with HD. We identified a subgroup of patients suspected of suffering from active progressive disease and prospectively followed them after performing dynamic MRI studies of the cervical spine.nnnRESULTSnTwenty-two patients were identified as having a disease consistent with HD, of whom 8 were defined as having actively progressive disease. Seven of these 8 patients demonstrated clear dynamic compression of the cervical spine during neck flexion. The patient who did not demonstrate the typical MRI changes associated with HD went on to develop generalized ALS.nnnCONCLUSIONSndMRI has a practical role in patients presenting with progressive upper-limb distal weakness and atrophy, and the presence of characteristic changes typical of HD may suggest a more optimistic prognosis.

Postradiation lower motor neuron syndrome: case series and literature review.

A variety of neurological syndromes has been described after irradiation of the distal spinal cord and cauda equina, mainly as treatment for testicular cancer and lymphoma. One of these syndromes is a rare lower motor neuron syndrome, manifested by flaccid paraparesis. Medical files of patients with postradiation lower motor neuron syndrome treated in our neuromuscular clinic from 2005 to 2012 were reviewed. The diagnosis was based on past irradiation of the distal spinal cord and cauda equina, slowly progressive lower limb weakness, characteristic electrophysiological studies, and no alternative diagnosis. In addition, a systematic review of the literature on similar cases was performed using PUBMED. We identified five patients with postradiation lower motor neuron syndrome in our clinic charts. Three of them were irradiated due to seminoma, and the other two due to lymphoma. 45 additional similar cases were found in a literature search, mainly male (89xa0%), with testicular cancer (67xa0%), irradiated at mean age of 33xa0years, with an average irradiation dose of 5,225xa0cGy (range 3,000–14,600), and a latency period between irradiation and symptoms onset ranging from 3xa0months to 27xa0years (average 9xa0years). Magnetic resonance imaging was done only in few, showing gadolinium enhancement of the cauda equina in close to half of them (7/16). Our patients and those previously described in the literature form a distinct clinical and electrophysiological syndrome that might be more frequent then previously expected, and should be not overlooked.