The Syndrome of transient Headache and Neurological Deficits with cerebrospinal fluid Lymphocytosis, or HANDL syndrome, is a rare neurological condition. It is characterized by temporary episodes of severe, migraine-like headaches accompanied by a range of neurological symptoms. Despite the often alarming, stroke-like presentation of its symptoms, HANDL is considered a benign condition. The neurological deficits that occur during an episode resolve completely on their own.
Characteristic Symptoms of HANDL
The headache is severe and pulsating, similar to a migraine, and can be accompanied by nausea, vomiting, and sensitivity to light and sound, lasting from hours to days. Individuals may experience between one and twelve episodes, separated by symptom-free periods. The entire course of the illness usually resolves within a three-month period.
The neurological symptoms vary but often mimic a stroke. The most common deficits are sensory disturbances like numbness or tingling (hemiparesthesia), affecting about 78% of individuals. Aphasia, or difficulty with language, is seen in roughly two-thirds of cases, and weakness on one side of the body (hemiparesis) occurs in over half. Visual disturbances can also occur but are less common.
Potential Causes and Triggers
The exact cause of HANDL syndrome remains unknown, but research points toward several possibilities. The leading theory suggests it may be an inflammatory or autoimmune condition, possibly triggered by a preceding infection. In about one-third of cases, the onset of HANDL symptoms is preceded by signs of a viral illness, which may initiate an immune response that mistakenly targets the nervous system.
Another theory involves changes in cerebral blood flow, suggesting that blood vessels in the brain may be temporarily affected. This could be related to cortical spreading depression, a phenomenon also implicated in migraine aura. This wave of neuronal depolarization could trigger the release of inflammatory substances that affect blood vessels and cause the headache and neurological deficits.
The Diagnostic Journey
Diagnosing HANDL syndrome involves a process of exclusion, as its symptoms can resemble more serious conditions like stroke, meningitis, or encephalitis. Because there is no single definitive test, physicians must rule out other potential causes for the symptoms.
Brain imaging, such as a computed tomography (CT) scan or magnetic resonance imaging (MRI), is a standard part of the diagnostic workup. In cases of HANDL, these imaging studies are usually normal, which helps to exclude conditions like stroke or tumors.
A lumbar puncture, or spinal tap, is a procedure for confirming a diagnosis. Analysis of the cerebrospinal fluid (CSF) reveals a characteristic finding: a high level of lymphocytes, a type of white blood cell. The CSF may also show elevated protein levels. These findings, combined with normal brain imaging and the transient nature of the symptoms, help establish the diagnosis.
Treatment Approaches and Outlook
There is no specific cure for HANDL syndrome, as the episodes resolve on their own. Treatment is supportive and focuses on managing the severe headaches with pain medications similar to those used for migraines. Hospitalization may be necessary during the initial evaluation to rule out other serious conditions and to manage severe symptoms.
The long-term outlook for individuals with HANDL syndrome is excellent. The condition is benign and does not result in permanent neurological damage. While a person may experience several episodes, the syndrome is self-limiting and resolves within a few months, with most individuals returning to their normal state of health.