Stiff-person syndrome initially diagnosed as functional movement disorder
Gender: Female
A paediatric patient with progressive stiffness, axial dystonia, painful spasms, exaggerated startle and loss of mobility was initially diagnosed with functional movement disorder. Progressive deterioration prompted investigation for genetic dystonia and Wilson disease. Anti-dystonia treatments were unsuccessful, while clonazepam substantially improved stiffness. The patient was subsequently diagnosed with probable stiff-person syndrome; anti-GAD65 antibodies were repeatedly >250 IU/mL. Source: https://pmc.ncbi.nlm.nih.gov/articles/PMC10875472/
Symptoms
Left foot stiffness
Neck stiffness
Shoulder stiffness
Painful back spasms
Difficulty walking
Frequent falls
Progressive loss of independent walking
Worsening handwriting
Progressive speech difficulty
Progressive difficulty with self-care
Difficulty feeding herself
Family history
- Mother: Hyperthyroidism / Graves' disease
- Father: Pancreatic cancer; died in his mid-40s from complications
- Family history: Breast cancer
- Family history: Colon cancer
Clinical observations
Axial/truncal rigidity
Sternocleidomastoid stiffness
Thoracolumbar rigidity
Progressive abnormal spinal curvature
Dystonic/twisting movements of the left hand
Dystonic/twisting movements of the left foot
Abnormal left-hand posturing
Abnormal left-foot posturing
Exaggerated startle response
Progressive proximal limb involvement
Later distal muscle involvement
Facial muscle involvement
Writer's cramp
Initially normal sensation
Initially normal deep tendon reflexes
Eventually unable to walk unaided
Eventually non-verbal
Sternocleidomastoid stiffness
Thoracolumbar rigidity
Progressive abnormal spinal curvature
Dystonic/twisting movements of the left hand
Dystonic/twisting movements of the left foot
Abnormal left-hand posturing
Abnormal left-foot posturing
Exaggerated startle response
Progressive proximal limb involvement
Later distal muscle involvement
Facial muscle involvement
Writer's cramp
Initially normal sensation
Initially normal deep tendon reflexes
Eventually unable to walk unaided
Eventually non-verbal