Table 1.

Causes of secondary intracranial hypertension (SIH).

Causes of SIH	No. of Patients
Neoplastic (acute lymphocytic lymphoma, meningiosarcoma)	7
Infectious (viral meningitis, adenovirus, and influenza encephalitis, Staphylococcus toxic shock, Lemierre syndrome)	6
Drug-induced (minocycline, lithium, doxycycline, Accutane)	6
Cerebrospinal fluid pleocytosis, unknown cause	3
Periodic fever syndromes (Muckle-Wells)	3
Chiari malformation	2
Arachnoid cyst	2
Autoimmune disorders (scleroderma, Behçet)	2
Cerebral sinus venous thrombosis	2
Pineal gland cyst, associated with mild mass effect	1
Hydrocephalus, unspecified	1
Demyelinating disorder, unknown	1

There were 36 patients included with SIH. Various causes fell within 12 different categories.