Unilateral Muscle Fasciculations with Progressive Pattern in a 42-Year-Old Woman

Case at a Glance

A 42-year-old woman presents with a 6-month history of progressive muscle fasciculations primarily affecting her right side, accompanied by intermittent right leg weakness. The patient has a significant family history of multiple sclerosis in two siblings.

Patient's Story

The patient reports experiencing muscle fasciculations for approximately 6 months that began around her right shoulder blade, described as 'flapping like a bird wing' and visible to others. The fasciculations subsequently progressed to involve her right flank area above the kidney region, right pectoral muscle, right thigh, right palm, and right upper bicep. She describes the twitching pattern as similar to 'the type of twitching you may see when you barely touch a cat and their fur crawls' rather than pulsing movements. The fasciculations have occurred once on her left lower bicep, and her right eye has had continuous twitching for about 4 months, which was noted by her ophthalmologist. The patient clarifies that these episodes do not occur simultaneously but represent the chronological progression of affected areas. She also reports intermittent weakness in her right leg during ambulation, describing it as painful and requiring her to 'brace herself better to use it or put weight on it.' The frequency of symptoms is increasing over time.

Initial Assessment

Physical examination reveals visible muscle fasciculations primarily on the right side of the body. The patient appears otherwise healthy with a BMI of 30.1 (height 5'3", weight 170 lbs). Neurological examination shows intermittent right lower extremity weakness during ambulation.

The Diagnostic Journey

Given the unilateral distribution of fasciculations, family history of multiple sclerosis, and associated weakness, further neurological evaluation was warranted. The patient expressed concern about whether this represented benign fasciculation syndrome or a more serious neurological condition.

Final Diagnosis

Pending neurological evaluation for suspected central nervous system demyelinating disease versus motor neuron disease, given the family history and clinical presentation.

Treatment Plan

Referral to neurology for comprehensive neurological evaluation including MRI brain and spinal cord, nerve conduction studies, and electromyography. Consider CSF analysis if indicated based on imaging findings.

Outcome and Follow-up

Patient advised to maintain symptom diary and return for urgent evaluation if weakness progresses or new neurological symptoms develop. Regular monitoring scheduled pending specialist evaluation.