"De Novo" Hypercapnic Respiratory Failure Unmasking Neuromuscular Disorders: Experiences From a Tertiary Care Center and Review of Literature.

OBJECTIVES: Neuromuscular disorders could have respiratory involvement early or late into illness. Rarely, patients may present with a hypercapnic respiratory failure (with minimal motor signs) unmasking an underlying disease. There are hardly any studies which have addressed the spectrum and challenges involved in management of this subset, especially in the real-world scenario. METHODS: A retrospective study comprising consecutive patients hospitalized with hypercapnic respiratory failure as the sole/dominant manifestation. The clinical-electrophysiological spectrum, phrenic conductions, diaphragm thickness, and outcomes were analyzed. RESULTS: Twenty-seven patients were included, the mean age was 47.29 (SD 15.22) years, and the median duration of respiratory symptoms was 2 months (interquartile range [IQR] 1-4). Orthopnea was present in 23 patients (85.2%) and encephalopathy in 8 patients (29.6%). Phrenic nerve latencies and amplitudes were abnormal in 83.3% and 95.6%, respectively. Abnormal diaphragm thickness was noted in 78.5%. Based on a comprehensive electrophysiological strategy and paraclinical tests, an etiology was established in all. Reversible etiologies were identified in 17 patients (62.9%). These included myasthenia gravis (anti-AChR and MuSK), inflammatory myopathy, riboflavin transporter deficiency neuronopathy, Pompe disease, bilateral phrenic neuritis, and thyrotoxicosis. Respiratory onset motor neuron disease was diagnosed in 8 patients (29.6%). Despite diaphragmatic involvement, a functional respiratory recovery was noted at discharge (45%) and last follow-up (60%). Predictors for good outcomes included female sex, normal nerve conductions, and recent-onset respiratory symptoms. DISCUSSION: A good functional recovery was noted in most of the patients including respiratory onset motor neuron disease. A systematic algorithmic approach helps in proper triaging, early diagnosis, and treatment. Clinical and electrodiagnostic challenges and observations from a tertiary care referral center are discussed.

Hoffman syndrome with the classic sign of myoedema and an unusual finding of systolic heart failure.

A man in his 20s presented with a 6-year history of calf muscle hypertrophy, proximal muscle weakness and muscle cramps. Along with this, he also had patchy hair loss, facial puffiness and slurring of speech. On examination, he had mild symmetrical proximal muscle weakness, a delayed relaxation phase of his deep tendon reflexes and a rare neurological sign of myoedema. His laboratory investigations revealed elevated thyroid-stimulating hormone levels with high creatine kinase levels, and an echocardiogram showed left ventricular systolic dysfunction. He was diagnosed with Hoffman syndrome, a rare pseudohypertrophic myopathy associated with severe and prolonged hypothyroidism. He had an excellent response to thyroid hormone replacement.

Clinical Spectrum, Therapeutic Outcomes and Prognostic predictors in Paraneoplastic Neurological Syndromes - Experiences from a Tertiary Care Center in India.

BACKGROUND: Paraneoplastic Neurological Syndromes (PNSs) are a heterogeneous group of immune-mediated disorders that often precede tumor diagnosis. There are few systematic studies on the spectrum and follow-up of PNSs. OBJECTIVE: To analyze the clinical spectrum, associated tumors, antibody profile, outcomes, and prognostic predictors in a cohort of PNSs admitted in a tertiary care center. METHODS: This retrospective study included 97 patients (2008-2019). PNSs were further classified as "classical," "nonclassical," "definite," and "possible." Clinical profile, diagnostic strategies, therapeutic options, and predictors of outcomes were identified. RESULTS: The median age was 54 years (range 17-81). Thirty-nine (40.2%) had classical PNS, and 58 (59.8%) had nonclassical PNS, 74 (76.3%) had "Definite" PNS while 23 (23.7%) had "Possible" PNS. Cerebellar degeneration, peripheral neuropathy, and encephalopathy were the three most common neurological syndromes. Tumors were diagnosed in 66 (68%) patients; Lung cancer was the most common primary tumor. Antibodies were positive in 52 (53.6%). Anti-Yo antibody and anti-Ma2 antibody were the most common antibodies. The majority (57.7%) received immunotherapy in addition to definitive treatment for the tumor. A good outcome was seen in 53 (54.6%). Factors associated with good outcome were: early diagnosis, mRS <3 at presentation, absence of metastatic disease, and adjuvant immunotherapy. CONCLUSION: A high index of clinical suspicion is essential for early diagnosis and prompt management of PNS, especially the nonclassical syndromes. Multimodality diagnostic imaging techniques and antibody profiling play a crucial role in the diagnosis. A favorable prognosis can be expected with the judicious use of immunotherapy and definitive treatment of malignancy.

Utility of stimulus induced after discharges in the evaluation of peripheral nerve hyperexcitability: Old wine in a new bottle?

Limited literature is available on stimulus induced after discharges (SIAD) in patients with peripheral nerve hyperexcitability (PNH). The aim of the study was to examine the diagnostic utility of SIAD in the diagnosis and monitoring of primary PNH disorders. In this retrospective study, we studied 26 patients who were admitted with a diagnosis of primary PNH to the department of Neurology from January 2013 to April 2019. Their clinical profile, immunological characteristics were extracted from the database and nerve conduction studies were relooked for the presence of SIAD. 76% of patients in the primary PNH cohort had SIAD with 90% of them being voltage-gated potassium channel complex antibody positive; predominantly against contactin-associated protein-2 antigen and rest being paraneoplastic. There was also resolution of SIAD following treatment indicating reversible hyperexcitability. SIAD is a sensitive marker for Primary PNH syndrome with monitoring and diagnostic implications.