Pinar Kahraman Koytak

Medial plantar and dorsal sural nerve conduction studies increase the sensitivity in the detection of neuropathy in diabetic patients

OBJECTIVE Clinical utility of nerve conduction studies (NCS) of the medial plantar and dorsal sural nerves in the early detection of polyneuropathy have already been shown separately. However, at present, there is no data about the combined assessment of these two nerves in distal sensory neuropathy. In the present study, we aimed to evaluate the medial plantar and dorsal sural NCS in a group of diabetic patients with distal sensory neuropathy (DSN) and in healthy controls. METHODS Thirty healthy and 30 diabetic adult patients were included. In all subjects, peripheral motor and sensory NCS were performed bilaterally with surface electrodes on the lower limbs including medial plantar and dorsal sural nerves. In addition, motor and sensory nerves were studied unilaterally on the upper limb. RESULTS In all patients, nerve action potential (NAP) amplitudes of sural and superficial peroneal nerves were within normal ranges, but in the patient group mean value was significantly lower than in the controls. Among clinically defined 30 DSN patients, medial plantar NAP amplitude was abnormal in 18 (60%) and dorsal sural nerve amplitude was abnormal in 13 (40%) of the patients bilaterally. Additionally, the onset NCV of the dorsal sural nerve was significantly slower in patients than controls (P=0.038). Evaluation of both of these nerves increased the sensitivity up to 70% in the detection of neuropathy. CONCLUSIONS Bilateral NCS assessment of both of the medial plantar and dorsal sural nerves together increases the rate of diagnosis of diabetic distal sensory neuropathy compared to assessment of either of these nerves. SIGNIFICANCE Assessment of medial plantar in addition to dorsal sural NCS together increases the sensitivity in the detection of neuropathy and allows earlier diagnosis, especially when routine NCS are normal.

Assessment of symptomatic diabetic patients with normal nerve conduction studies: utility of cutaneous silent periods and autonomic tests.

Established electrophysiological methods have limited clinical utility in the diagnosis of small‐fiber neuropathy (SFN). In this study, diabetic patients with clinically diagnosed SFN were evaluated with autonomic tests and cutaneous silent periods (CSPs). Thirty‐one diabetic patients with clinically suspected SFN and normal nerve conduction studies were compared with 30 controls. In the upper extremities (UE), the CSP parameters did not differ statistically between the patient and control groups, whereas, in the lower extremities (LE), patients had prolonged CSP latencies (P = 0.018) and shortened CSP durations (P < 0.001). The sensitivity of the CSP duration was 32.6%, and the specificity was 96.7%. The expiration‐to‐inspiration ratios and amplitudes of the sympathetic skin responses in the lower extremities were also reduced. Our findings indicate that the diagnostic utility of CSPs was higher than that of the autonomic tests to support the clinically suspected diagnosis of SFN. Muscle Nerve, 2011

Headache During Air Travel: An Unusual Cause of Reversible Cerebral Vasoconstriction Syndrome

Reversible cerebral vasoconstriction syndrome (RCVS) is a rare condition characterized by segmental and reversible narrowing of the cerebral arteries. High altitude has been reported as an extremely rare cause for this distinctive syndrome. Here, we report a case of RCVS and propose air travel as the triggering factor. A 51-year-old female patient experienced an intense thunderclap headache during air travel, which persisted through her entire trip. On the second day after landing back home, she presented with right hemiparesis accompanying the headache at a facility different from where the authors are located. Diffusion weighted magnetic resonance imaging (DWI) and cranial magnetic resonance angiography (MRA) had revealed a pattern of restriction on the left frontoparietal cortical region and segmental vasoconstrictions that were more predominant on the posterior circulation consecutively. A diagnosis of RCVS was considered. When the patient was discharged with verapamil therapy, she had normal neurological status. Two days later, she was hospitalized at our hospital with an attack of weakness of the left leg, which lasted for 10 min. The DWI showed no infarctions. However, segmental vasoconstrictions on bilateral posterior cerebral arteries, anterior cerebral arteries (ACAs), and middle cerebral arteries were observed on cranial MRA. Her therapy regimen was changed to nimodipine and dexamethasone. On the follow-up, her left-sided weakness and thunderclap headache attacks had recurred until the last attack, which persisted. No significant blood pressure changes were observed at that time. The DWI revealed acute infarctions on ACA territory and bilateral head of the caudate nuclei. MRA showed that the vasoconstrictions were more prominent on the mentioned arteries. Her therapy was switched to intravenous nimodipine and the dose was gradually increased up to 1.5 mg/hour and dexamethasone was stopped. Under this treatment, she developed no further symptoms or infarctions. When she was discharged 1 month after her first symptom on oral From the Department of Neurology, Marmara University Faculty of Medicine, Istanbul, Turkey (H. Alibas, S. Ceferova, P. Kahraman Koytak, K. Uluc, I. Midi, N. Tuncer Elmaci, S. Aktan, and T. Tanridag).

Motor-Unit Number Estimation Is Sensitive in Detecting Motor Nerve Involvement in Patients with Carpal Tunnel Syndrome

Background and Purpose We compared the motor-unit number estimation (MUNE) findings in patients who presented with signs and/or findings associated with carpal tunnel syndrome (CTS) and healthy controls, with the aim of determining if motor-unit loss occurs during the clinically silent period and if there is a correlation between clinical and MUNE findings in CTS patients. Methods The study investigated 60 hands of 35 patients with clinical CTS and 60 hands of 34 healthy controls. Routine median and ulnar nerve conduction studies and MUNE analysis according to the multipoint stimulation method were performed. Results The most common electrophysiological abnormality was reduced conduction velocity in the median sensory nerve (100% of the hands). The MUNE value was significantly lower for the patient group than for the control group (p=0.0001). ROC analysis showed that a MUNE value of 121 was the optimal cutoff for differentiating between patients and controls, with a sensitivity of 63.3% and a specificity of 68.3%. MUNE values were lower in patients with complaints of numbness, pain, and weakness in the median nerve territory (p<0.05, for all comparisons), and lower in patients with hypoesthesia than in patients with normal neurological findings (p=0.023). Conclusions The MUNE technique is sensitive in detecting motor nerve involvement in CTS patients who present with sensorial findings, and it may be useful in detecting the loss of motor units during the early stages of CTS. Larger-scale prospective clinical trials assessing the effect of early intervention on the outcome of these patients would help in confirming the possible benefit of detecting subclinical motor-unit loss in CTS.

A Case with Leukoencephalopathy with Brainstem and Spinal Cord Involvement and Elevated Lactate (LBSL) with Its Characteristic Clinical and Neuroimaging Findings

Leukoencephalopathy with brainstem and spinal cord involvement and elevated lactate (LBsL) is a recently described white matter disorder, characterized by slowly progressive cerebellar, pyramidal, and dorsal column dysfunction [1]. It is a very rare autosomal recessive mitochondrial disease; however, its unique pattern of magnetic resonance imaging (MRI) findings distinguishes it from the other leukoencephalopathies and is therefore pathognomonic [1–8]. Distinct MRI findings of nonhomogeneous cerebral white matter abnormalities with selective involvement of the brainstem and spinal cord and specific magnetic resonance spectroscopy (Mrs) abnormalities are the striking neuroradiological features of the disease. We herein report a case of LBsL.

A database for screening and registering late onset Pompe disease in Turkey

The aim of this study was to search for the frequency of late onset Pompe disease (LOPD) among patients who had a myopathy with unknown diagnosis registered in the pre-diagnostic part of a novel registry for LOPD within a collaborative study of neurologists working throughout Turkey. Included in the study were 350 patients older than 18 years who have a myopathic syndrome without a proven diagnosis by serum creatine kinase (CK) levels, electrodiagnostic studies, and/or muscle pathology, and/or genetic tests for myopathies other than LOPD. Acid alpha glucosidase (GAA) in dried blood spot was measured in each patient at two different university laboratories. LOPD was confirmed by mutation analysis in patients with decreased GAA levels from either both or one of the laboratories. Pre-diagnostic data, recorded by 45 investigators from 32 centers on 350 patients revealed low GAA levels in a total of 21 patients; from both laboratories in 6 and from either one of the laboratories in 15. Among them, genetic testing proved LOPD in 3 of 6 patients and 1 of 15 patients with decreased GAA levels from both or one of the laboratories respectively. Registry was transferred to Turkish Neurological Association after completion of the study for possible future use and development. Our collaborative study enabled collection of a considerable amount of data on the registry in a short time. GAA levels by dried blood spot even from two different laboratories in the same patient may not prove LOPD. LOPD seemed to be rarer in Turkey than in Europe.

Paraneoplastic pandysautonomia as a manifestation of non-small cell lung cancer

Pandysautonomia is a severe and rare clinical condition characterized by widespread sympathetic and parasympathetic dysfunction. Consideration of whether symptoms and presentation are acute, subacute, or chronic is often helpful in establishing a differential diagnosis. The underlying mechanisms leading to pure pandysautonomia are unclear; however, there is some evidence suggestive of an immune-mediated pathogenesis. Herein, we report a case with pandysautonomia as a paraneoplastic manifestation of non-small cell lung cancer that had an excellent response to symptomatic and supportive treatments, as well as IVIG therapy.

Cutaneous silent period in myofascial pain syndrome

Introduction: An increased response to painful stimuli without spontaneous pain suggests a role of central hyperexcitability of pain pathways in the pathogenesis of myofascial pain syndrome (MPS). In this study we aimed to test the hypothesis that spinal pain pathways are affected in MPS. We used cutaneous silent period (CSP) parameters to demonstrate the hyperexcitability of spinal pain pathways in MPS. Methods: Twenty‐nine patients diagnosed with MPS and 30 healthy volunteers were included in the study. The CSP recordings were performed in the right upper and left lower extremities. Results: In both upper and lower extremities, patients had prolonged CSP latencies (P = 0.034 and P = 0.049 respectively) and shortened CSP durations (P = 0.009 and P = 0.008, respectively). Discussion: Delayed and shortened CSP in MPS patients implies dysfunction in the inhibitory mechanism of the spinal/supraspinal pain pathways, suggesting central sensitization in the pathogenesis of MPS and supporting our research hypothesis. Muscle Nerve 57: E24–E28, 2018

Brainstem Reflexes in Systemic Lupus Erythematosus Patients Without Clinical Neurological Manifestations

INTRODUCTION We aimed to assess central and peripheral nervous system involvement in systemic lupus erythematosus (SLE) patients without any neurological signs and symptoms by performing electrophysiological investigations. METHODS Thirty-eight SLE patients and 35 healthy volunteers participated in this study. Peripheral nerve conduction and brainstem reflexes were evaluated by performing nerve conduction studies (NCSs) and blink reflex (BR) and masseter inhibitory reflex (MIR) recordings. RESULTS Eleven patients (29%) had an abnormality in at least 1 NCS parameter, and 1 (2.6%) patient was diagnosed with polyneuropathy. The number of patients with abnormal BR and MIR was 23 (60.5%) and 14 (37%), respectively. The contralateral R2 latency of BR and the silent period 1 (SP1) latency of MIR were significantly prolonged in the patients compared with the controls (p=0.015 and p<0.001, respectively). CONCLUSION This study showed that irrespective of peripheral nervous system involvement, brainstem reflexes could be affected in SLE patients even without clinical neurological findings. Brainstem reflex abnormalities suggested that the functional integrity of the inhibitory or excitatory interneurons in the lateral caudal pons and lateral medulla is disturbed in SLE patients.

Medial plantar-to-radial amplitude ratio: does it have electrodiagnostic utility in distal sensory polyneuropathy?

Purpose of the study: We proposed a new electrophysiological parameter medial plantar (MP)-to-radial amplitude ratio (MPRAR), similar to sural-to-radial amplitude ratio (SRAR), in the diagnosis of distal sensory polyneuropathy (DSP), based on the concept that distal nerves are affected more and earlier than proximal nerves in axonal neuropathies. We aimed to investigate the diagnostic sensitivity of this parameter in diabetic DSP, together with sensitivities of SRAR and MP nerve action potential (NAP) amplitude. Materials and Methods: In 124 healthy controls and 87 diabetic patients with clinically defined DSP and normal sural responses, we prospectively performed sensory nerve conduction studies (NCS), and evaluated the MP NAP amplitude, MPRAR and SRAR values. We determined the lower limits of normal (LLN) of these parameters in the healthy controls and calculated their sensitivities and specificities in detecting DSP in diabetic patients. Results: MP nerve amplitude and MPRAR values were significantly lower in the patient group, compared to controls. However, SRAR values did not differ significantly between the two groups. The LLN of MP NAP amplitude was found to be 4.1 μV. The cutoff values for SRAR and MPRAR were determined as 0.24 and 0.16, respectively. MPRAR was abnormal in 21.8% of patients. However, the most sensitive parameter in detection of DSP was MP NAP amplitude, which showed a sensitivity of 31% and a specificity of 100%. Conclusions: Although MPRAR is more sensitive than SRAR in detecting DSP, it does not provide additional diagnostic yield to the assessment of MP NCS alone in diabetic DSP patients with normal sural responses.