The combination of generalized seizures with ataxia and dementia is not seen in which one of the following conditions?
(B) Neuronal ceroid lipofuscinosis
(E) Mitochondrial encephalomyelopathy
(A) Progressive myoclonic epilepsy (PME) is a slowly progressive autosomal recessive disorder occurring in late childhood or early adulthood. Generalized seizures, ataxia, and dementia are prominent features. Linkage analysis has shown that the gene responsible is located on the long arm of chromosome 21q22.3. The common causes of PME are neuronal ceroid lipofuscinosis, mitochondrial encephalomyelopathy, sialidosis, Lafora disease, Baltic myoclonus, GM2 gangliosidosis, and dentatorubropallidoluysian atrophy. (Evidente, 475–490)
Alien limb occurs significantly in case of
(B) corticobasal degeneration
(C) Parkinson disease (PD)
(E) carbon monoxide intoxication
(B) Alien limb is defined as the lack of recognition of movement in the affected limb, or a feeling that one limb is foreign associated with observable involuntary motor activity. The upper extremity is the most frequently affected limb. Signs include the failure to perceive ownership of one's limb in the absence of visual cues, an impression that the seen limb is foreign, personification of the affected limb, and autonomous motor activity deemed by the patient as beyond voluntary control. Alien limb syndrome is a well-established part of corticobasal degeneration. It is reported to complicate the course of the disease in nearly 50% of cases. Vascular etiology is most commonly reported in ischemic or hemorrhagic lesions of the anterior cerebral artery. Surgical lesions such as corpus callosotomy and thalamotomy have been associated with alien limb. Other causes of alien limb include Alzheimer disease and Creutzfeldt–Jacob disease. (Hanna, 135–145)
Which of the following is true of the dorsal prefrontal circuit?
(A) It originates in the frontal convexity and projects to the nucleus accumbens.
(B) It involves the ventral posterolateral nucleus of the thalamus.
(C) Lesion of the circuit results in deficits in executive function and motor programming.
(D) The Mini-Mental State Examination is typically impaired when there is a lesion of the prefrontal cortex.
(E) The prefrontal circuit is particularly spared in Huntington disease.