Exploring the Connection Between Sleep and Cluster Headache: A Narrative Review

Abstract

Cluster headache is a rare form of headache associated with sleep and even speculated to be a manifestation of a sleep disorder rather than a primary headache. Cluster headache exhibits both circadian and circannual rhythmicity. While attacks often occur during sleep, the implication that cluster headaches might be involved with rapid eye movement (REM) sleep phases has neither been fully established nor refuted. The regulatory mechanisms governing sleep including hypothalamic activity and the autonomic nervous system response may play a role. Hypothalamic activation has been observed in cluster headache patients during positron emission tomography testing, but only during attacks. While sleep apnea is associated with morning headaches in general, the link between sleep-disordered respiration and cluster headache remains elusive. Hypoarousal during sleep and periods of hypoxia are associated with cluster headache, the latter likely involving inflammatory processes rather than apnea. Further study is needed, as cluster headaches represent a serious primary cephalgia that is incompletely understood.

Keywords: Chronic cluster headache; Cluster headache; Cluster headache syndrome; Sleep.

Fig. 1

The unilateral pain of cluster headache is associated with trigeminal nerve involvement and can result in severe pain, typically around one eye. Art courtesy of Todd Cooper of Coyote Studios, Green Valley, California

Fig. 2

The hypothalamus constitutes less than 1% of the brain by volume, but it is involved in numerous important processes, including regulation of the limbic system and regulation of the body’s autonomic nervous system. It regulates arousal during sleep, the synthesis of many hormones, and the body’s circadian clock. The nuclei in the brain stem and spinal autonomic ganglia receive afferent inputs from the periphery, which are delivered via the spinal cord and brainstem to the hypothalamus. The autonomic nervous system regulates the trigeminal nerves of the face which may play a role in headache pain as well as rhinorrhea, lacrimation, and nasal congestion associated with cluster headache. Art courtesy of Todd Cooper of Coyote Studios, Green Valley, California