However, the average survival from onset of disease is six months. CJD is uniformly fatal. Most patients succumb to pneumonia or from inanation. Early clinical features can be subtle and include malaise, altered personality, emotional lability, and sleep disturbances. Other findings may include hallucinations or delusional ideation.
Later manifestations are a rapidly progressive dementia and ataxia with myoclonus.
Patients may become mute, or exhibit cortical blindness, with rigidity and spasticity. The subacute form, the most common, is characterized by presence of prodromal symptoms before onset of worsening dementia and ataxia. The intermediate type is marked by a long period in which focal or diffuse neurological signs are present before onset of rapidly progressive dementia. Patient with the rare amyotrophic form of CJD have lower motor neuron signs with neurogenic atrophy of muscle along with dementia. The spongiform encephalopathy of CJD is seen microscopically to exhibit many round to oval vacuoles varying in size from one to 50 microns in size in the neuropil of cortical gray matter.