Transient Headache and Neurologic Deficits With Cerebrospinal Fluid Lymphocytosis (HaNDL syndrome) is a headache disorder in which individuals experience severe to moderate headache attacks, neurological symptoms, and an increase in the amount of a type of white blood cell in the cerebrospinal fluid (lymphocytic pleocytosis). HaNDL syndrome is most often diagnosed in adulthood, although individuals with ages ranging from 7 to 52 have been reported with this condition. The most common neurological symptoms associated with HanDL syndrome include: weakness on one side of the body (hemiparesis), a feeling of altered sensation down one side of the body (hemisensory disturbances), and a loss of the ability to understand or express speech (aphasia). These symptoms usually last between 15 minutes and 2 hours. The cause of HaNDL syndrome is not well understood; however, researchers have suggested a few potential causes, including migraines, inflammation of the tissue that lines the brain and spinal cord, and viral infections. For some individuals, HaNDL syndrome may resolve without treatment, while for others, management of headache and neurological symptoms may be needed.

Headaches associated with HaNDL syndrome may be limited to one side of the head or may involve both sides. They can last from one hour to a week and are often associated with nausea, vomiting, and sensitivity to light. Some individuals may also have a fever. Often, the headache occurs after neurological symptoms begin.

Neurological symptoms usually last between 15 minutes and 2 hours, although this may range from 5 minutes to 3 days. Most people additionally experience repeated headaches and symptoms for weeks to months after the initial attack. Neurological symptoms usually differ from one episode to the next.

The most common neurological symptoms are:

• Weakness on one side of the body (hemiparesis)
• A feeling of altered sensation down one side of the body (hemisensory disturbances)
• A loss of the ability to understand or express speech (aphasia)

Visual signs and symptoms occur less commonly and may include:

• Decreased vision
• Loss of vision on the left or right side of the visual field (homonymous hemianopsia)
• Perceived flashes of light (photopsias)

People with this condition may also experience swelling of the nerve that runs from the retina in the eye to the brain (papilledema) and dysfunction of the cranial nerve in the brain (sixth nerve palsy). Occasionally, individuals may have episodes of confusion.

• MRI of the head
• Electroencephalography (EEG)
• Angiography
• Bacterial, viral, and fungal studies
• Lumbar puncture to collect cerebrospinal fluid
• Blood testing including liver function tests, electrolytes and renal (kidney) function, and thyroid function
• Urine tests including metabolic screen

Diagnostic guidelines were published in the International Classification of Headache Disorders, 3rd edition, which state that HaNDL syndrome is classified as a headache associated with a noninfectious inflammatory disease. The diagnostic criteria includes:

• Episodes of migraine-like headache lasting at least four hours, during or shortly before neurological symptoms occur.
• The finding of an abnormally increased level of a type of white blood cells (lymphocytes) in the cerebrospinal fluid (lymphocytic pleocytosis).
• Either worsening or improving neurological symptoms depending on the level of lymphocytic pleocytosis.
• Exclusion of other similar conditions.

The diagnostic guidelines are freely available to the general public and can be viewed on the International Classification of Headache Disorders website.