Autopsy was performed on a 30‐year‐old man who died of Lafora disease. This patient, one of two siblings with Lafora disease, had onset of symptoms at age 13 years and a clinical course of 17 years. He had frequent tonic‐clonic convulsions and myoclonus, followed by dementia. Due to dysphagia resulting from strong spasms of the pharyngo‐esophageal muscles, he underwent gastrostomy. Routine laboratory data, including liver function tests and an electrocardiogram (ECG), were within the normal range. The autopsy revealed degeneration with polyglucosan accumulations in myocardiac muscle cells, liver cells, and smooth muscle cells of the esophago‐gastrointestinal tract, urinary system, and blood vessels, as well as in striated muscle cells in the skeletal muscles and neurons in the nervous system. In the central nervous system (CNS), numerous intraneuronal polyglucosan accumulations (Lafora bodies) were present in the following structures (listed in decreasing order of density): the substantia nigra, olivary nuclei (superior and inferior), vestibular nucleus (medial and lateral), thalamus, globus pallidus (lateral segment), dentate nucleus, gracile and cuneate nuclei, cerebral cortex (frontal, temporal, parietal and occipital), amygdala, nucleus basalis of Meynert, neostriatum, hypothalamus, reticular formation of the brain stem, locus ceruleus, red nucleus, mesencephalic central gray, solitary nucleus, ambiguus nucleus, dorsal vagal nucleus, and some other cranial nerve nuclei. In the mammillary bodies or subthalamic nucleus no perikaryonal Lafora bodies were found, although a considerable number of intraneuritic Lafora bodies were noted. Electron microscopically, Lafora bodies were composed of granular material and irregular filaments (about 6 nm in diameter), which were immunohistochemically positive for ubiquitin and tau. No Lafora bodies were reactive with Gallyas stain. This study is the first to have revealed that in Lafora disease smooth muscle cells can be systemically involved in specific degeneration for Lafora disease. In this patient, severe myoclonus could potentially spread over the pharynx and esophagus and cause pharyngo‐esophageal spasm and dysphagia. Because of the very long clinical course, the histopathology of this patient may represent the full extension of the degeneration that is specific for Lafora disease.
