Corneal nerve fiber involvement in chronic inflammatory demyelinating polyneuropathy.

BACKGROUND: Despite the primary myelin-related pathophysiology, small fiber neuropathy (SFN) and axonal degeneration are also considered to be involved and associated with disabling symptoms and impaired quality of life in chronic inflammatory demyelinating polyneuropathy (CIDP). Demonstration of SFN usually requires complex or invasive investigations. OBJECTS: In vivo corneal confocal microscopy (IVCCM) has evolved as a non-invasive, easily applied method for quantification of small fiber involvement in peripheral nerve disorders. We aimed to investigate the potential role of IVCCM in CIDP. METHODS: In this cross-sectional study, 15 patients with CIDP underwent assessment with clinical disability scales, neuropathic pain (NP) and autonomic symptom questionnaires, nerve conduction studies, and IVCCM. IVCCM parameters were analyzed and compared to those from 32 healthy controls. RESULTS: Corneal nerve fiber density (CNFD) and corneal nerve fiber length (CNFL) were significantly decreased in the CIDP group, compared to those in controls (p = 0.03 and p = 0.024, respectively). Langerhans cells and fiber tortuosity were increased in CIDP patients (p = 0.005 and p = 0.001, respectively). IVCCM parameters were significantly lower in patients with NP compared to those in patients without NP. CONCLUSION: IVCCM shows promise as a non-invasive complementary biomarker in the assessment of demyelinating polyneuropathies, providing insights into the potential pathophysiology of these non-length-dependent neuropathies.

Reference jitter values for the sternocleidomastoid muscle with concentric needle electrodes.

BACKGROUND: The aim of this study was to establish reference jitter values for the voluntary activated sternocleidomastoid (SCM) muscle using a concentric needle electrode (CNE). METHODS: The study included 39 healthy participants (20 female and 19 male) aged 18-77 y. Jitter was expressed as the mean consecutive difference (MCD) of 80-100 consecutive discharges. Filters were set at 1 and 10 kHz. The mean MCDs for all participants were pooled, and the mean value +2.5 SD was accepted as the upper limit for the mean MCD. The upper limit for individual MCD was calculated using +2.5 SD of the upper 10th percentile MCD for individual participants. RESULTS: Mean age of the participants was 45 ± 14.5 y. Mean MCD was 16.20 ± 2.23 µs (range: 12-21 µs), and the upper limit of normal for mean MCD was 21.8 µs. The mean value for 823 individual jitters was 23.3 ± 4.61 µs (range: 6.6-36.9 µs), and the upper limit of normal for each individual jitter was 34.6 µs. CONCLUSIONS: The present findings indicate that upper normal limit for mean MCD is 22 µs and for individual data it is 35 µs.

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.

The reliability of medial and lateral plantar nerve recordings in healthy elderly individuals.

The aim of this study was to investigate the reliability of medial plantar (MP) and lateral plantar (LP) nerve conduction studies (NCS) in healthy individuals aged >65 years, and to obtain reference values for this age group. The study included 81 healthy subjects. MP response was absent in only 2 subjects, but LP response could not be obtained bilaterally in 43 of the 81 subjects. Regression analysis showed that MP NCS could be reliably performed in those aged ≤ 72 years and normal values for MP nerve in individuals aged 66-72 years would be strongly against a large-fiber neuropathy. However, LP response was absent in 53.1 % of the healthy elderly subjects; therefore, we think it is unreliable to study the LP nerve in this age group.

Palmar cutaneous nerve conduction in patients with carpal tunnel syndrome.

OBJECTIVE: This study aimed to assess palmar cutaneous branch of the median nerve (PCBm) conduction in patients with clinically diagnosed carpal tunnel syndrome (CTS), to compare PCBm conduction with that of the median and ulnar nerves, and to determine the PCBm conduction abnormality rate in patients with CTS. MATERIALS AND METHODS: The study included 99 hands of 60 patients with clinical CTS and 38 hands of 38 healthy controls. Sensory nerve conduction study (NCS) was performed on the median nerve, ulnar nerve, and PCBm, and onset latency, conduction velocity and amplitude were recorded. Additionally, differences in latency and velocity between the median nerve and PCBm, and the difference in latency between the median and ulnar nerves were calculated. RESULTS: In all, 56% of the patients with CTS had abnormal PCBm conduction. Additionally, in 7 of 8 hands with abnormal sensation--both in the thenar eminence and abnormal sensory distribution along the main branch--NCS of the PCBm was also abnormal. CONCLUSIONS: The PCBm is not ideal as a comparator nerve for the neurophysiological diagnosis of CTS. The frequency of PCBm abnormality in CTS patients may be related to the concomitant damage in both of these nerves. Additionally, the present findings may help explain, at least in part, why patients with CTS often exhibit sensory involvement beyond the classical median nerve sensory borders.

Accuracy and reliability of magnetic resonance imaging in the diagnosis of idiopathic intracranial hypertension.

PURPOSE: To determine the diagnostic utility of brain magnetic resonance imaging (MRI) findings in patients with idiopathic intracranial hypertension (IIH) and to investigate the significance of evaluating radiological findings together with neurological and ophthalmological data in the diagnosis of IIH. MATERIALS AND METHODS: All consecutive patients diagnosed with IIH in our tertiary neuro-ophthalmology center between January 1, 2018 and March 15, 2020, were included in the study. The clinical, radiological, and ophthalmological findings of IIH patients were compared with the control group with similar demographic characteristics. RESULTS: A total of 98 patients, 49 cases and 49 controls, were included in the study. Lateral ventricular index had the highest area under the curve (AUC) value (0.945) for prediction of disease group followed by sella height category (AUC = 0.915) and optic nerve tortuosity (AUC = 0.855) According to the multivariate model we developed, caudate index (OR = 0.572, 95% CI 0.329-0.996), lateral ventricle index (OR = 3.969, 95% CI 1.851-8.509) and bilateral optic nerve tortuosity (OR = 22,784, 95% CI 2.432-213.450) were significant predictors for disease group. CONCLUSION: Tortuosity in the optic nerve, lateral ventricular index and caudate index can be used as MRI parameters supporting the diagnosis of IIH in clinically suspicious cases. A holistic approach to the clinical and radiological findings of the cases in the diagnosis of IIH can prevent overdiagnosis and enable early correct diagnosis.

Physical and mental fatigue in myasthenia gravis and its correlation with other symptoms.

INTRODUCTION: Muscle weakness and easy fatigability are the clinical hallmarks of myasthenia gravis (MG). However, fatigue perception, which can be seen quite often in myasthenic patients, and its effect on the quality of life, irrespective of motor deficit, has not been elucidated yet. The aim is to evaluate the frequency of fatigue in myasthenic patients with nearly full muscle strength and the effect of fatigue on quality of life by assessing its correlation with other symptoms. METHODS: Fifty-three patients with ocular or mild generalized MG in remission or minimal manifestations completed the questionnaires measuring the severity of MG and quality of life (MG Composite Scale and MG-Activities of Daily Living Profile). Both patient group and control group (53 healthy volunteers)completed the scales assessing fatigue [Fatigue Assessment Scale (FAS) and Fatigue Impact Scale (FIS)], depression [Beck Depression Inventory (BDI)] and sleep (Epworth Sleepiness Scale). Disease severity was assessed using MG Foundation of America (MGFA) and MGFA Post-Intervention Status classifications. RESULTS: FAS, FIS physical and BDI scores were significantly higher in patients compared to the control group (p = 0.003, p = 0.001, and p = 0.003, respectively) and fatigue was associated with depression and daytime sleepiness. Inpatient group, depressive symptoms and daytime sleepiness were higher in females (p = 0.019 and p = 0.013). The mean values of FIS total and cognitive scores were higher in patients with generalized MG (p = 0.033 and p = 0.045). Fatigue scores correlated with motor signs. DISCUSSION: Fatigue can be seen in MG independently from muscle weakness and is an important symptom worsening the quality of life.

Acute flaccid myelitis outbreak through 2016-2018: A multicenter experience from Turkey.

AIM: We aim to describe the demographic characteristics, etiology, neurophysiology, imaging findings, treatment, prognosis, and prognostic factors of acute flaccid myelitis. METHODS: The clinical data, laboratory test and, magnetic resonance imaging (MRI) results of pediatric patients diagnosed with acute flaccid myelitis according to the Centers for Disease Control criteria between August 1, 2016, and December 31, 2018, from 13 centers in Turkey were reviewed. RESULTS: Of the 34 cases identified, 31 were confirmed (91.2%). Eighteen patients (55.9%) were boys. The median patient age was 4 years (interquartile range 2.5-6.9 years). Most of the patients were admitted in 2018 (n = 27). A preceding history of a febrile illness was reported in all patients, with a median of 4 days (interquartile range 3-7 days) before symptom onset. Thirty-one patients had T2 hyperintensity on spinal MRI, and 18 patients had cerebrospinal fluid pleocytosis. The most common infectious agents were entero/rhinoviruses (n = 5) in respiratory specimens. All patients except one received immunotherapy either alone or in combination. Among 27 patients with follow-up data 24 had persistent weakness. Involvement of four limbs together with an abnormal brain MRI at onset were associated with a poor prognosis. CONCLUSION: The number of patients with acute flaccid myelitis increased since 2012, spiking with every 2-year interval, largely in the pediatric population. The median age decreases with every outbreak. Clinicians should be aware of the clinical picture for early collection of specimens and early start of rehabilitation programs. Further studies are needed to better characterize the etiology, pathogenesis, risk factors, and treatment of this rare condition.

Diagnostic Errors in Initial Misdiagnosis of Optic Nerve Sheath Meningiomas.

Importance: Diagnostic errors can lead to the initial misdiagnosis of optic nerve sheath meningiomas (ONSM), which can lead to vision loss. Objective: To identify factors contributing to the initial misdiagnosis of ONSM. Design, Setting, and Participants: We retrospectively reviewed 35 of 39 patients with unilateral ONSM (89.7%) who were seen in the tertiary neuro-ophthalmology practice at Emory University School of Medicine between January 2002 and March 2017. The Diagnosis Error Evaluation and Research taxonomy tool was applied to cases with missed/delayed diagnoses. Exposures: Evaluation in a neuro-ophthalmology clinic. Main Outcomes and Measures: Identifying the cause of diagnostic errors for patients who initially received a misdiagnosis who were found to have ONSM. Results: Of 35 patients with unilateral ONSM (30 women [85.7%]; mean [SD] age, 45.26 [15.73] years), 25 (71%) had a diagnosis delayed for a mean (SD) of 62.60 (89.26) months. The most common diagnostic error (19 of 25 [76%]) was clinician assessment failure (errors in hypothesis generation and weighing), followed by errors in diagnostic testing (15 of 25 [60%]). The most common initial misdiagnosis was optic neuritis (12 of 25 [48%]), followed by the failure to recognize optic neuropathy in patients with ocular disorders. Five patients who received a misdiagnosis (20%) underwent unnecessary lumbar puncture, 12 patients (48%) unnecessary laboratory tests, and 6 patients (24%) unnecessary steroid treatment. Among the 16 patients who initially received a misdiagnosis that was later correctly diagnosed at our institution, 11 (68.8%) had prior magnetic resonance imaging (MRI) results that were read as healthy; 5 (45.5%) showed ONSM but were misread by a non-neuroradiologist and 6 (54.5%) were performed incorrectly (no orbital sequence or contrast). Sixteen of the 25 patients (64%) had a poor visual outcome. Conclusions and Relevance: Biased preestablished diagnoses, inaccurate funduscopic examinations, a failure to order the correct test (MRI brain/orbits with contrast), and a failure to correctly interpret MRI results were the most common sources of diagnostic errors and delayed diagnosis with worse visual outcomes and increased cost (more visits and tests). Easier access to neuro-ophthalmologists, improved diagnostic strategies, and education regarding neuroimaging should help prevent diagnostic errors.

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.

Topiramate and accommodation: Does topiramate cause accommodative dysfunction?

OBJECTIVE: To investigate the accommodation function in topiramate users. DESIGN: Case-control clinical study. PARTICIPANTS: The participants included 16 controls and 22 patients using 100 mg/kg topiramate who were diagnosed with migraine according to the International Classification of Headache Disorders, second edition criteria. METHODS: One-minute dynamic measurements of refraction with accommodation stimuli of 0 D, 2 D, 2.5 D, 3 D, 4 D, and 5 D were obtained using the open field refractometer WAM-5500 in. RESULTS: In most of the accommodation stimuli ranges (0 D, 2.5 D, 3 D, and 5 D), topiramate users had a significantly higher accommodative lag compared with controls (p = 0.028, p = 0.014, p = 0.011, and p = 0.011, respectively). The most important causes of accommodative lag were found to be accommodation stimulus and inclusion in the topiramate group (p < 0.001, R2 = 0.32, 95% CI 0.22-0.37 and 0.42-0.91, respectively). Multivariate linear regression analysis revealed that the 2 most important predictors of accommodative lag were accommodation stimulus and age (p < 0.001, r = 0.51, 95% CI 0.31-0.32 and 0.67-0.69, respectively) CONCLUSIONS: Even after adjustment for age, accommodative lag is greater across several accommodative stimulus levels in patients using topiramate, which may be related to visual symptoms in topiramate users.

Severe neuro-Behcet's disease treated with a combination of immunosuppressives and a TNF-inhibitor.

Abstract/ Resumo Behcet's disease (BD) is a multisystem inflammatory disorder characterized by recurrent oral and genital ulcers, skin lesions and uveitis. The nervous system involvement of BD, neuro-Behcet's disease (NBD), is one of the important causes of mortality of the disease. Herein, we present a 29-year-old male with parenchymal NBD who has progressed rapidly and was managed with an uncommon aggressive immunosuppresive combination therapy. The patient first presented six years ago with vertigo and difficulty in talking and walking. On examination, he had oral ulcers, acneiform lesions on the torso, genital ulcer scar, dysartria, and ataxia. Along with the magnetic resonance imaging (MRI) findings, the patient was diagnosed as NBD. After pulse methylprednisolone (1g/day, 3 days) and 8 courses of 1g/month iv cylophosphamide therapy, he was put on azathioprine and oral methlyprednisolone. On the 4th year of the maintenance therapy, he was admitted with NBD relapse which was treated with 3 days of iv 1g pulse methlyprednisolone. One year after the last relapse, the patient voluntarily stopped medications and presented with global aphasia, right hemihypoesthesia and quadriparesis. MRI findings were suggestive of NBD relapse. After exclusion of infection, pulse methylprednisolone was started but no improvement was observed. Considering the severity of the NBD, the patient was put on methylprednisolone (1mg/kg/day), iv cylophosphamide (1g) and adalimumab 40 mg/14 days subcutaneously with appropriate tuberculosis prophylaxis. Neurological examination and MRI findings after 4 weeks showed dramatic improvement however patient developed pulmonary tuberculosis. Methylprednisolone dose was decreased (0.5mg/kg/day) and quadruple antituberculosis therapy was started. Patient was discharged with 5/5 muscle strength in extremities without any respiratory symptoms 2 months after first presentation. Prompt introduction of immunosuppressive therapy is crucial in NBD. Although combination of TNF inhibitors and cyclophoshamide is a rare therapeutic approach, it may be life-saving. However a higher awareness is required for opportunistic infections.

Postcoital internal carotid artery dissection presenting as isolated painful horner syndrome: a case report.

Postcoital artery dissection is a rare condition. Here we report a 40-year-old male patient with painful Horner syndrome related to postcoital internal carotid artery (ICA) dissection. In neurologic examination of the patient, semiptosis, enophthalmus, and myosis were observed on the left side. There were no carotid bruits. On T1-weighted and fat-suppressed cranial MRI, hyperintensity consistent with intramural hematoma was observed within cervical and temporal petrous segments of left ICA. On cervical and cranial MRA, marked decrease in the calibration of C1 and C2 segments of the left ICA was remarkable. The patient was diagnosed as left ICA dissection and anticoagulant therapy was initiated. A prominent improvement was noted in clinical findings during two months of followup period.