Persistent anterograde amnesia following limbic encephalitis associated with antibodies to the voltage-gated potassium channel complex.

OBJECTIVE: Limbic encephalitis (LE) associated with antibodies to the voltage-gated potassium channel complex (VGKC) is a potentially reversible cause of cognitive impairment. Despite the prominence of cognitive dysfunction in this syndrome, little is known about patients' neuropsychological profile at presentation or their long-term cognitive outcome. METHODS: We used a comprehensive neuropsychological test battery to evaluate cognitive function longitudinally in 19 patients with VGKC-LE. RESULTS: Before immunotherapy, the group had significant impairment of memory, processing speed and executive function, whereas language and perceptual organisation were intact. At follow-up, cognitive impairment was restricted to the memory domain, with processing speed and executive function having returned to the normal range. Residual memory function was predicted by the antibody titre at presentation. CONCLUSIONS: The results show that, despite broad cognitive dysfunction in the acute phase, patients with VGKC-LE often make a substantial recovery with immunotherapy but may be left with permanent anterograde amnesia.

Deep brain stimulation of the anterior cingulate cortex: targeting the affective component of chronic pain.

Deep brain stimulation (DBS) has shown promise for relieving nociceptive and neuropathic symptoms of refractory chronic pain. We assessed the efficacy of a new target for the affective component of pain, the anterior cingulate cortex (ACC). A 49-year-old man with neuropathic pain underwent bilateral ACC DBS. Patient-reported outcome measures were collected before and 2 years after surgery using a Visual Analogue Scale, Short-Form 36 quality of life survey, McGill pain questionnaire, EuroQol-5D questionnaires (EQ-5D; Health State) and neuropsychological assessments. The patient improved with DBS. Two years after surgery, the Visual Analogue Scale decreased from 6.7 to 3.0, McGill pain questionnaire improved by 42% and EQ-5D Health State increased by 150%. Stimulating the ACC at 130 Hz, 330 µs and 3 V facilitated neuropathic pain relief. The DBS remained efficacious during the 2-year follow-up period. Affective ACC DBS can relieve chronic neuropathic pain refractory to pharmacotherapy and restore quality of life.

Catatonia causing permanent cognitive impairment: a case study.

OBJECTIVE: We describe a case of psychogenic malignant catatonia resulting in permanent cognitive impairment. BACKGROUND: Catatonia is a neuropsychiatric syndrome characterized by catalepsy, negativism, mutism, muscular rigidity, and mannerisms, often accompanied by autonomic instability and fever. Little is known about the long-term cognitive consequences of the syndrome. METHOD: Medical history includes neurologic examination, neuropsychological evaluation, electroencephalographic data, magnetic resonance imaging, sodium amytal interview, and treatment with electroconvulsive therapy. RESULTS: Selective deficits in executive function and an anterograde amnesia were evident a week post-ECT treatment and continued to be present at follow-up after 2 years and 8 months. CONCLUSION: The permanent cognitive impairments are considered in the context of catatonia as a frontal lobe syndrome.