Multifocal hypometabolic correlates to deficits of verbal memory in mesial temporal lobe epilepsy.

BACKGROUND AND OBJECTIVES: Neuropsychological research on mesial temporal lobe epilepsy (MTLE) often highlights material-specific memory deficits, but a lesion-focused model may not accurately reflect the underlying networks that support episodic memory in these patients. Our study evaluated the pathophysiology behind verbal learning/memory deficits as revealed by hypometabolism quantified through 18-fluorodeoxyglucose positron emission tomography (FDG-PET). METHODS: This retrospective study included thirty presurgical patients with intractable unilateral MTLE who underwent interictal FDG-PET and verbal memory assessment (12 females, mean age: 38.73 years). Fluorodeoxyglucose-positron emission tomography mapping was performed with voxel-based mapping of glucose utilization to a database of age-matched controls to derive regional Z-scores. Neuropsychological outcome variables included scores on learning and recall trials of two distinct verbal memory measures validated for use in epilepsy research. Pearson's correlations evaluated relationships between clinical variables and verbal memory. Linear regression was used to relate regional hypometabolism and verbal memory assessment. Post hoc analyses assessed areas of FDG-PET hypometabolism (threshold Z ≤ -1.645 below mean) where verbal memory was impaired. RESULTS: Verbal memory deficits correlated with hypometabolism in limbic structures ipsilateral to language dominance but also correlated with hypometabolism in networks involving the ipsilateral perisylvian cortex and contralateral limbic and nonlimbic structures. DISCUSSION: We conclude that traditional models of verbal memory may not adequately capture cognitive deficits in a broader sample of patients with MTLE. This study has important implications for epilepsy surgery protocols that use neuropsychological data and FDG-PET to draw conclusions about surgical risks.

Numb chin syndrome as a presentation for acute myeloid leukemia relapse post-hematopoietic cell transplant: Case report and review of literature.

NCS is defined as reduced or absent sensation in the chin and lower lip within the distribution of the mental or inferior alveolar nerves. Although commonly associated with local trauma, NCS can indicate an underlying malignancy or can be the presenting symptom of cancer recurrence. We describe a 6-year-old female patient with AML and t(8,21) who underwent allogeneic HCT. Five months post-HCT, the patient presented with right-sided facial pain and numbness in her chin and lower lip consistent with NCS. Two weeks later, the patient had bone marrow relapse indicating AML recurrence. Although NCS remains a rare diagnosis especially in children, in the context of leukemia, it usually indicates an advanced disease or could be a sign of recurrence, and is commonly associated with grim prognosis. Further research is needed to study the link between NCS and specific cytogenetic abnormalities.