Dear Sir,

I have read with interest the article of Marino et al. [1] on “Tarlov cysts: clinical evaluation of an Italian cohort of patients” in a recent issue of your esteemed journal. They examined 157 patients with MRI evidence of symptomatic Tarlov cysts. Clinical picture was correlated with size and number of cysts detected by MRI. Almost all patients suffered perineal or lower back pain; 54 (34.4 %) complained of sphincter and 46 (29.3 %) of sexual disorders. Average Hamilton Depression Rating Scale score was 18.1 (mild depression).

In our series of >200 cases of spontaneous intracranial hypotension, we observed a CSF leak from Tarlov cysts in 3. All patients suffered from orthostatic headache and underwent with lumbar epidural blood patch with autologous (EBP) blood with recovery.

Spontaneous intracranial hypotension (SIH) is a rare and probably under-recognized condition associated with diminished cerebrospinal fluid (CSF) volume and pressure [2]. Sometimes SIH is associated with underlying connective tissue disorders. The most common cause of SIH is CSF leakage from a spinal meningeal diverticulum, perineural cyst (Tarlov cysts) or simple dural tear, even if the source of the CSF loss remains cryptic on neuroimaging [2]. The diagnosis of SIH is suggested by the presence of orthostatic headache, dizziness, and tinnitus, accompanied by distinctive neuroimaging findings [2] based on compensatory venous hypervolemia, including diffuse pachymeningeal enhancement, subdural fluid collections, dilatation of the dural sinuses and spinal epidural plexus, and enlargement of the pituitary gland. Sometimes brain MRI can also show brain sagging. The rupture of Tarlov cysts may cause the CSF leakage resulting in SIH which has as its main symptom orthostatic headache [3, 4]. Treatment is usually conservative with bed rest and overhydration. In recent years, treatment with EBP is becoming gold standard [5].

I would only like to point out that Tarlov cysts in addition to the disorders mentioned in the article of Marino et al. (perineal or lower back pain; sphincter and sexual disorders) can also cause SIH presenting with orthostatic headache as main symptom.