Micrographia is small handwriting. It is most often recognized in association with the extrapyramidal features of idiopathic Parkinson’s disease (indeed it may be the presenting sign), but may occasionally occur with other parkinsonian syndromes (e.g., progressive supranuclear palsy [PSP]) or in isolation with focal lesions of the midbrain or basal ganglia. In Parkinson’s disease, handwriting may initially be of normal size but then become progressively smaller, slower, and more illegible as writing proceeds, an example of parkinsonian fatigue, a gradual decline in the amplitude and speed of initiation of voluntary movements. Such "slow" micrographia may be distinguished from "fast" micrographia in which letters are small throughout although written at normal speed without fatigue, which may be seen in PSP or other pallidal pathologies.
There is a poor correlation between micrographia and the side, severity or duration of classical parkinsonian features, and its response to levodopa preparations is very variable. These observations, along with reports of isolated micrographia with cortical lesions demonstrated by neuroimaging, suggest that the anatomical basis of micrographia may be at the level of the cortex (dominant parietal lobe) rather than the basal ganglia.
Micrographia has also been described following large right anterior cerebral artery infarcts and lacunar infarcts involving the putamen and genu of the internal capsule.
McLennan JE, Nakano K, Tyler HR, Schwab RS. Micrographia in Parkinson’s disease. Journal of the Neurological Sciences 1972; 15: 141-152
Scolding NJ, Lees AJ. Micrographia associated with a parietal lobe lesion in multiple sclerosis. Journal of Neurology, Neurosurgery and Psychiatry 1994; 57: 739-741