The anterior nucleus of thalamus (ANT) is a key component of the hippocampal system for episodic memory. The ANT consist of 3 subnuclei with distinct connectivity with the subicular cortex, retrosplenial cortex, and mammillary bodies. Via its connections with the anterior cingulate and orbitomedial prefrontal cortex, the ANT may also contribute to reciprocal hippocampal-prefrontal interactions involved in emotional and executive functions. As in other thalamic nuclei, neurons of the ANT have 2 different state-dependent patterns of discharge, tonic and burst-firing; some ANT neurons also contribute to propagation of the theta rhythm, which is important for mechanisms of synaptic plasticity of the hippocampal circuit. Clinical and experimental evidence indicate that damage of the ANT or its inputs from the mammillary bodies are primarily responsible for the episodic memory deficit observed in Wernicke-Korsakoff syndrome and thalamic stroke. Experimental models also indicate that the ANT may have a role in the propagation of seizure activity both in absence and in focal seizures. Because of its central connectivity and possible role in propagation of seizure activity, the ANT has become an attractive target for deep brain stimulation (DBS) for treatment of medically refractory epilepsy. The ANT is one of the nuclei preferentially affected in prion disorders, such as fatal familial insomnia, but the relationship between ANT involvement and the clinical manifestations of these disorders remains unclear. The connectivity patterns and electrophysiology of the ANT have been the subject of several reviews.(1-4.)

Nicholas Child is a clinical neuromodulation and epilepsy fellow at Mayo Clinic Rochester. SUMMARYMedically refractory epilepsy remains a major medical problem worldwide. Although some patients are eligible for surgical resection of seizure foci, a proportion of patients are ineligible for a variety of reasons. One such reason is that the foci reside in eloquent cortex of the brain and therefore resection would result in significant morbidity. This retrospective study reports our experience with a novel neurostimulation technique for the treatment of these patients. We identified three patients who were ineligible for surgical resection of the intracranially identified seizure focus because it resided in eloquent cortex, who underwent therapeutic trial of focal cortical stimulation delivered through the subdural monitoring grid. All three patients had a significant reduction in seizures, and two went on to permanent implantation, which resulted in longterm reduction in seizure frequency. In conclusion, this small case report provides some evidence of proof of concept of the role of targeted continuous neocortical neurostimulation in the treatment of medically refractory focal epilepsy, and provides support for ongoing investigations into this treatment modality.

A 55-year-old man presented with seizures characterized by "tightening" of the right side and variable loss of awareness. EEG showed focal epileptogenic abnormalities over left and midline central regions. CS is an autosomal dominant condition of hamartomas and tumors.1 MRI is abnormal in 35%, commonly showing dysplastic gangliocytomas of cerebellum, meningiomas, and vascular malformations.2 CS has not been reported presenting with partial epilepsy and focal cortical dysplasia.

Neurons contain different functional somatodendritic and axonal domains, each with a characteristic distribution of voltage-gated ion channels, synaptic inputs, and function. The dendritic tree of a cortical pyramidal neuron has 2 distinct domains, the basal and the apical dendrites, both containing dendritic spines; the different domains of the axon are the axonal initial segment (AIS), axon proper (which in myelinated axons includes the node of Ranvier, paranodes, juxtaparanodes, and internodes), and the axon terminals. In the cerebral cortex, the dendritic spines of the pyramidal neurons receive most of the excitatory synapses; distinct populations of γ-aminobutyric acid (GABA)ergic interneurons target specific cellular domains and thus exert different influences on pyramidal neurons. The multiple synaptic inputs reaching the somatodendritic region and generating excitatory postsynaptic potentials (EPSPs) and inhibitory postsynaptic potentials (IPSPs) sum and elicit changes in membrane potential at the AIS, the site of initiation of the action potential.

Tawil syndrome (ATS) is a rare cause of periodic paralysis. It is characterized by periodic paralysis, cardiac dysrhythmias, and distinct physical characteristics. [1][2][3] We report a patient in whom the diagnosis was made in the fifth decade after he presented with a fixed myopathy, and in whom electrodiagnostic testing after treatment mirrored the patient's report of improved muscle strength despite an absence of objective clinical strengthening.A 43-year-old man presented with progressive proximal muscle weakness. A diagnosis of Becker muscular dystrophy (BMD) had been made in childhood based on calf hypertrophy, myopathic abnormalities on muscle biopsy (right deltoid, before availability of dystrophin staining), and mildly elevated creatine kinase (330 U/ L). He was referred when his son presented with similar symptoms, suggesting an autosomal dominant condition rather than x-linked Becker dystrophy. The patient reported slowly worsening gait and difficulty getting out of chairs and walking up stairs. He also described day-today fluctuations in muscle strength but did not describe well-defined spontaneous attacks of weakness.On examination, there was wasting of the sternocleidomastoid and upper pectoral muscles, moderate proximal upper and lower limb weakness (Medical Research Council [MRC] Grade 4 to 41), and normal distal power. There was mild retrognathia, low-set ears, and tapered fingers with clinodactyly. His electrocardiogram (ECG) showed a prolonged QTc of 484 ms. A needle electromyography (EMG) study showed subtle myopathic changes without myotonia (right deltoid, biceps, and first dorsal interosseous). Sensory nerve conduction studies were normal. Motor nerve studies showed normal conduction velocities but a low right ulnar compound muscle action potential (CMAP) amplitude of 3.0 mV (abductor digiti minimi, normal 6.0 mV) that normalized with exercise (7 mV, 130% increase) but was followed by a postexercise decrement of 86% (McManis long-exercise protocol). 4 Genetic testing confirmed a c652C>T mutation in exon 2 of KCNJ2.Within days of starting acetazolamide 250 mg twice daily and oral potassium supplements, he reported improvement in baseline muscle strength (e.g., being able to lift his arms above his head), and later, on a dose of 500 mg twice daily, a reduction in the frequency and severity of the variable weakness. Clinical examination confirmed unchanged proximal weakness. A McManis test after 15 days of treatment showed an improved baseline right ulnar CMAP amplitude of 4.4 mV but an attenuated exercise-related increment (45% vs. 130%) and attenuated postexercise decrement (53% vs. 86%) vs. pretreatment.Although described in other muscle channelopathies, the unusual feature of this case is the presentation in adulthood of a chronic progressive myopathy, rather than discrete paralytic attacks, and the potential partial reversibility of the weakness with treatment. In addition, the value of repeated exercise CMAP testing is illustrated by the reduction in CMAP decrement postexercise, as well...