Sudden onset of sleep caused by hypothalamic infarction: a case report.

BACKGROUND: Hypothalamic lesions, such as tumors and demyelinating diseases, reportedly cause abnormal sleepiness. However, stroke involving the hypothalamus has rarely been described. Here, we report a patient with infarction restricted to the hypothalamus who presented with sudden onset of sleep. CASE PRESENTATION: A 42-year-old woman with a history of migraine without aura presented with irresistible sleepiness and developed several episodes of sudden onset of sleep. Neurological examinations were unremarkable except for partial left Horner syndrome. Brain magnetic resonance imaging (MRI) revealed a high-intensity lesion restricted to the left hypothalamus on diffusion-weighted and fluid-attenuated inversion recovery MRI images. Cerebrospinal fluid (CSF) orexin-A levels obtained on hospital day 3 after her sleepiness had resolved were normal (337 pg/mL; normal > 200 pg/mL). Serum anti-nuclear and anti-aquaporin 4 (AQP4) antibodies and CSF myelin basic protein and oligoclonal band were negative. A small hypothalamic infarction was suspected, and the patient was treated with intravenous edaravone and argatroban, as well as oral clopidogrel. Three months later, there had been no clinical relapse, and the hypothalamic lesion had almost disappeared on follow-up MRI. No new lesion suggestive of demyelinating disease or tumor was observed. CONCLUSION: Hypothalamic stroke should be considered a cause of sudden onset of sleep.

Cerebrospinal fluid orexin-A levels in systemic lupus erythematosus patients presenting with excessive daytime sleepiness.

Objective Involvement of the hypothalamus is rare in patients with systemic lupus erythematosus (SLE). In this study, we measured cerebrospinal fluid (CSF) orexin-A levels in SLE patients with hypothalamic lesions to investigate whether the orexin system plays a role in SLE patients with hypothalamic lesions who present with excessive daytime sleepiness (EDS). Methods Orexin-A levels were measured in CSF from four patients with SLE who presented with hypothalamic lesions detected by MRI. Three patients underwent repeated CSF testing. All patients met the updated American College of Rheumatology revised criteria for SLE. Results Tests for serum anti-aquaporin-4 antibodies, CSF myelin basic protein and CSF oligoclonal bands were negative in all patients. All patients presented with EDS. Low to intermediate CSF orexin-A levels (92-180 pg/ml) were observed in three patients in the acute stage, two of whom (patients 1 and 2) underwent repeated testing and showed increased CSF orexin-A levels, reduced abnormal hypothalamic lesion intensities detected by MRI and EDS dissipation at follow-up. In contrast, CSF orexin-A levels were normal in one patient (patient 4) while in the acute stage and at follow-up, despite improvements in EDS and MRI findings. Patient 4 showed markedly increased CSF interleukin-6 levels (1130 pg/ml) and a slightly involved hypothalamus than the other patients. Conclusions Our findings suggest that the orexinergic system has a role in EDS in SLE patients with hypothalamic lesions. Furthermore, cytokine-mediated tissue damage might cause EDS without orexinergic involvement.

Relationship between cerebrospinal fluid concentrations of orexin A/hypocretin-1 and body composition in humans.

The hypothalamic neuropeptide orexin A (hypocretin-1) is a key signal in sleep/wake regulation and promotes food intake. We investigated the relationship between cerebrospinal fluid orexin A concentrations and body composition in non-narcoleptic human subjects with a wide range of body weight to gain insight into the role of orexin A in human metabolism. We collected cerebrospinal fluid and blood samples and measured body composition by bioelectric impedance analysis in 36 subjects (16 women and 20 men) with body mass indices between 16.24 and 38.10 kg/m2 and an age range of 19-80 years. Bivariate Pearson correlations and stepwise multiple regressions were calculated to determine associations between orexin A and body composition as well as biometric variables. Concentrations of orexin A in cerebrospinal fluid averaged 315.6 ±â€¯6.0 pg/ml, were comparable between sexes (p > 0.15) and unrelated to age (p > 0.66); they appeared slightly reduced in overweight/obese compared to normal-weight subjects (p = .07). Orexin A concentrations decreased with body weight (r = -0.38, p = .0229) and fat-free mass (r = -0.39, p = .0173) but were not linked to body fat mass (p > 0.24). They were inversely related to total body water (r = -0.39, p = .0174) as well as intracellular (r = -0.41, p = .0139) and extracellular water (r = -0.35, p = .0341). Intracellular water was the only factor independently associated with cerebrospinal fluid orexin A concentrations (p = .0139). We conclude that cerebrospinal fluid orexin A concentrations do not display associations with body adiposity, but are inversely related to intracellular water content. These cross-sectional findings suggest a link between orexin A signaling and the regulation of water homeostasis in humans.

Hypocretin Deficiency Associated with Narcolepsy Type 1 and Central Hypoventilation Syndrome in Neurosarcoidosis of the Hypothalamus.

We report a case of a 53-year-old man presenting with depressed alertness and severe excessive sleepiness in the setting of neurosarcoidosis. Neuroimaging demonstrated hypothalamic destruction due to sarcoidosis with a CSF hypocretin level of 0 pg/mL. The patient also experienced respiratory depression that presumably resulted from hypocretin-mediated hypothalamic dysfunction as a result of extensive diencephalic injury. This is a novel case, demonstrating both hypocretin deficiency syndrome, as well as respiratory dysfunction from destruction of hypocretin neurons and extensive destruction of key diencephalic structures secondary to the underlying neurosarcoidosis.

Neuromyelitis optica spectrum disorder presenting with repeated hypersomnia due to involvement of the hypothalamus and hypothalamus-amygdala linkage.

We report the case of a 46-year-old Japanese woman with neuromyelitis optica spectrum disorder presenting with repeated hypersomnia accompanied by decreased CSF orexin level. First episode associated with hypothalamic-pituitary dysfunction showed bilateral hypothalamic lesions that can cause secondary damage to the orexin neurons. The second episode associated with impaired memory showed a left temporal lesion involving the amygdala. The mechanism remains unknown, but the reduced blood flow in the hypothalamus ipsilateral to the amygdala lesion suggested trans-synaptic hypothalamic dysfunction secondary to the impaired amygdala. A temporal lesion involving the amygdala and hypothalamus could be responsible for hypersomnia due to neuromyelitis optica spectrum disorder.