Citations

ABSTRACT Introduction/Aims The clinical significance of stereotyped post‐F‐wave discharges remains uncertain. We aimed to characterize F‐wave‐induced repetitive discharges (FIRDs) and their associated clinical and electrodiagnostic findings. Methods We searched the Mayo Clinic electrodiagnostic database (January 1997–December 2025) using “F‐wave” and “repetitive discharges” and reviewed retrieved waveforms. FIRDs were defined by repetitive discharges following F‐wave activation, reproducible morphology within a train, and regular or semiregular firing. Results The study included 20 patients with FIRDs (median age 61 years, range 21–83 years; 10 male). Routine motor conduction attributes were normal in 90% of patients and F‐wave latencies were normal in all. FIRDs consisted of brief, reproducible discharges with a regular or semi‐regular firing pattern, individual durations of 2–10 ms, firing frequencies of 100–500 Hz, and amplitudes of 120–1000 μV. Neurogenic abnormalities on needle electromyography were seen in the distribution of the FIRD nerve in 65%. FIRDs were transient in a subset of patients who had repeat studies (5/5). Clinical and electrophysiological diagnoses included peripheral neuropathy (30%), radiculopathy (25%), polio (5%), brachial plexopathy (5%), and chronic inflammatory demyelinating polyradiculoneuropathy (5%). Six patients (30%) had no clinical or electrophysiological evidence of a neuromuscular disorder. Discussion FIRDs represent an uncommon electrophysiological phenomenon seen in both chronic neurogenic disorders and patients without neurologic disease. Recognition may aid waveform interpretation, but their presence alone does not establish a specific neuromuscular diagnosis.

ABSTRACT Background and Aims Nonsystemic vasculitic neuropathy classically presents as a painful asymmetric axonal neuropathy, multiple mononeuropathies or radiculoplexus neuropathy. Demyelinating electrophysiologic features are rare and may lead to misdiagnosis. We describe a patient with biopsy‐proven vasculitic neuropathy presenting as a severe symmetric demyelinating polyradiculoneuropathy. Methods Clinical, electrophysiologic, imaging, laboratory, and histopathologic findings are presented. Results A 57‐year‐old man developed acute ascending weakness, sensory loss, facial weakness, and areflexia following a febrile illness, with initial improvement before developing recurrent neurological decline 6 weeks after initial symptom onset despite treatment with intravenous immunoglobulin and plasma exchange. Cerebrospinal fluid protein was elevated. Nerve conduction studies demonstrated prolonged distal motor latencies, slowed conduction velocities, conduction block, and prolonged blink reflex latencies, fulfilling 2021 European Academy of Neurology/Peripheral Nerve Society electrodiagnostic criteria for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). MRI demonstrated mild but diffuse lumbosacral plexus enlargement and T2 hyperintensity. Sural nerve biopsy ultimately demonstrated evidence of epineurial inflammation and microvasculitis with ischemic nerve injury, accompanied by both increased rates of axonal degeneration (12%) and segmental demyelination (9%) on teased fiber analysis. Treatment with corticosteroids and rituximab resulted in complete neurological recovery. Interpretation Vasculitic neuropathy may closely mimic CIDP clinically, radiologically, and electrophysiologically. Clues to the vasculitis diagnosis were prominent neuropathic pain, dense denervation on electrophysiology, and poor response to typical CIDP treatment. Peripheral nerve biopsy remains a critical tool in the evaluation of atypical or treatment‐refractory inflammatory neuropathies.

This case report describes a 65-year-old man who experienced complete remission of cavin-4 immunoglobulin G (IgG) rippling muscle disease after receiving rituximab therapy.

Background Spontaneous intracranial hypotension (SIH) results from cerebrospinal fluid (CSF) leakage due to spinal dural tears or CSF–venous fistulas. Orthostatic headache is the hallmark presentation, though severe downward displacement of the brainstem may lead to altered consciousness or coma. Definitive treatments include targeted epidural blood patches, venous embolization, or surgical repair. Methods This article reviews the role of the Trendelenburg position as a temporizing measure in the acute management of SIH. We describe the correct technique, physiologic rationale, and practical considerations for its application, with attention to both therapeutic and diagnostic utility. Discussion Positioning the patient with the feet elevated above the head can reduce brain sag and provide short-term symptomatic relief while awaiting definitive treatment. Although the Trendelenburg position is widely used in practice, supporting evidence remains limited, and clinicians must be aware of its benefits, indications, and inherent limitations. Its appropriate application may assist in stabilizing patients with acute or severe SIH, particularly those with impaired consciousness, until more definitive interventions are pursued.