Meralgia paresthetica.

Meralgia paresthetica is a common but probably underrecognized syndrome caused by dysfunction of the lateral femoral cutaneous nerve. The diagnosis is based on the patient's description of sensory disturbance, often painful, on the anterolateral aspect of the thigh, with normal strength and reflexes. Sensory nerve conduction studies and somatosensory evoked potentials may be used to support the diagnosis, but both have technical limitations, with low specificity and sensitivity. Risk factors for meralgia paresthetica include obesity, tight clothing, and diabetes mellitus. Some cases are complications of hip or lumbar spine surgery. Most cases are self-limited, but a small proportion of patients remain with refractory and disabling symptoms. Treatment options include medications for neuropathic pain, neurolysis, neurectomy, and radioablation, but controlled trials to compare efficacy are lacking.

Insular Involvement in Cases of Epilepsy Surgery Failure.

BACKGROUND: Epilepsy surgery failure is not uncommon, with several explanations having been proposed. In this series, we detail cases of epilepsy surgery failure subsequently attributed to insular involvement. METHODS: We retrospectively identified patients investigated at the epilepsy monitoring units of two Canadian tertiary care centers (2004-2020). Included patients were adults who had undergone epilepsy surgeries with recurrence of seizures post-operatively and who were subsequently determined to have an insular epileptogenic focus. Clinical, electrophysiological, neuroimaging, and surgical data were synthesized. RESULTS: We present 14 patients who demonstrated insular epileptic activity post-surgery-failure as detected by intracranial EEG, MEG, or seizure improvement after insular resection. Seven patients had manifestations evoking possible insular involvement prior to their first surgery. Most patients (8/14) had initial surgeries targeting the temporal lobe. Seizure recurrence ranged from the immediate post-operative period to one year. The main modality used to determine insular involvement was MEG (8/14). Nine patients underwent re-operations that included insular resection; seven achieved a favorable post-operative outcome (Engel I or II). CONCLUSIONS: Our series suggests that lowering the threshold for suspecting insular epilepsy may be necessary to improve epilepsy surgery outcomes. Detecting insular epilepsy post-surgery-failure may allow for re-operations which may lead to good outcomes.

Neuromuscular Complications of Systemic Amyloidosis.

Systemic amyloidosis is characterized by extracellular deposition of insoluble fibrillar proteins in multiple tissues, frequently at a distance from the site of synthesis. The 2 most common forms, light chain (AL) and transthyretin (ATTR) amyloidosis can cause peripheral neuropathy and, rarely, myopathy. Diagnosis can be challenging, and abundant suspicion is required to identify patients. As neurological manifestations of amyloidosis may precede involvement of other organs by several years, recognizing amyloid neuropathy and myopathy are crucial, especially in this new and exciting era of effective therapies for AL and ATTR neuropathy. This review will focus on the neuromuscular manifestations of AL and ATTR amyloidosis, diagnostic approaches, and recent advances in the treatment of amyloid neuropathy.

Poor Yield of Routine Transthyretin Screening in Patients with Idiopathic Neuropathy.

BACKGROUND AND OBJECTIVES: Transthyretin familial amyloid polyneuropathy (TTR-FAP) is caused by a mutation in the transthyretin (TTR) gene. Although classically described as rapidly progressive and life-threatening, recent studies on TTR-FAP show significant genetic and phenotypic heterogeneity depending on geographic localization. In light of new therapeutic advances and their implication for patient management, the aim of our study was to determine the prevalence of TTR-FAP within patients with idiopathic neuropathy in a North American population. METHODS: We sequenced the TTR gene in a cohort of patients with idiopathic neuropathy. Genetic screening was performed in 110 patients from two neuromuscular clinics in Montreal, Canada. RESULTS: No variants of unknown significance or pathogenic mutations were detected in the TTR gene. CONCLUSION: Our study confirms that TTR-FAP is a rare entity in our patient population, and that diagnostic yield of screening all patients with idiopathic neuropathy is very low.