Clinical Reasoning: A 55-Year-Old Woman With Painless Hand Weakness and Atrophy.

Hand weakness is a frequent chief concern in neurology practice. We report a case of a 55-year-old woman presenting with a chronic, gradually worsening right hand weakness and atrophy, selectively affecting the thenar muscles, without any sensory symptoms. She had a history of carpal tunnel syndrome and previously underwent surgical carpal tunnel release. This case delves into the differential diagnosis of hand weakness and atrophy, emphasizing the significance of myotomal innervation in intrinsic hand muscles. Furthermore, it outlines a systematic approach to diagnosing an uncommon cause for a common clinical presentation, offering a comprehensive differential diagnosis, and exploring various possible causes.

Neuromuscular ultrasound: Impact on diagnosis and management.

INTRODUCTION/AIM: High-resolution ultrasound (HRUS) is increasingly used in evaluating neuromuscular conditions. Its potential advantages include its ability to discern anatomic information and make specific etiological diagnoses. Although many studies have demonstrated HRUS effectiveness, especially in mononeuropathies, more information is needed to better determine how often and to what extent useful information is obtained; how it influences diagnosis, clinical decision-making, and patient management; and how it is used with electrodiagnostic (EDx) studies. METHODS: A retrospective cohort study was performed on patients referred for HRUS at a university laboratory during 2021. Demographic information, referral diagnoses, clinical information, HRUS findings, and follow-up patient management were analyzed. For patients who had EDx, results were compared with HRUS. Determinations were made whether HRUS did or did not aid in the diagnosis. For patients in whom HRUS resulted in a diagnosis, determination was made whether it confirmed the diagnosis made clinically or by EDx but did not change management; added additional important information; and/or made a decisive impact on subsequent management. RESULTS: Five hundred two patients were analyzed, most referred for mononeuropathy, brachial plexopathy, and polyneuropathy. HRUS was abnormal in 81.7% of patients. HRUS added additional useful information in 79.0% and was decisive in management in 62.7%. In patients who also had abnormal EDx, HRUS resulted in decisive management in 49.5%. DISCUSSION: HRUS is an effective diagnostic tool that frequently adds localizing and structural information that is otherwise not obtainable by clinical and EDx evaluation. In a substantial number of patients selected for HRUS, it is decisive in guiding further management.

Clinical Reasoning: A 12-Year-Old Girl With Acute-Onset Diplopia, Dizziness, and Upbeat Nystagmus.

We report a case of a 12-year-old girl who presented with acute-onset diplopia, dizziness, and upbeat nystagmus. On examination, she had right internuclear ophthalmoplegia with right eye hypertropia and exotropia and impaired convergence. In addition, she also had spontaneous primary position symmetric upbeat nystagmus. In this report, we discuss the clinical approach with meticulous neuro-ophthalmologic examination and neuroanatomic localization in pediatric patients with acute-onset diplopia.

Pseudonystagmus in progressive supranuclear palsy.

Ocular oscillations often have critical role in diagnostic algorithm of neurodegenerative disorders. Nystagmus, if present in parkinsonian syndrome, suggests cerebellar involvement that is typical of multiple system atrophy. We found vertical jerky oscillations of the eyes during oculographic assessments using head-fixed corneal curvature trackers in six patients with progressive supranuclear palsy. The oscillations were eliminated by adequate head stabilization of the patients. Although this phenomenon gave the initial impression of "downbeat nystagmus", the oscillations were phase locked and frequency matched with subtle jerky head oscillations. We interpreted such jerky eye oscillations as "pseudonystagmus" representing the vestibulo-ocular reflex in response to involuntary subtle jerky head oscillations in our patients. This study further emphasizes the importance of head stabilization during instrumented or clinical assessment of gaze holding.