Disequilibrium in patients with posterior fossa arachnoid cysts.

BACKGROUND: Arachnoid cysts (AC) are benign, congenital malformations of the leptomeninges. In our experience, dizziness and vertigo are common complaints in patients with such cysts. OBJECTIVE: To quantify dizziness and imbalance in patients with arachnoid cysts in the posterior fossa using the Dizziness Handicap Inventory (DHI), Vertigo Symptom Scale Short-Form (VSS-SF) and Computerized Dynamic Posturography (CDP). We also wanted to investigate whether any dizziness and imbalance are reversible after surgical cyst decompression. METHODS: The study includes four patients with AC in the posterior fossa (two in the cerebellopontine angle and two supracerebellar in the midline) and 15 control subjects undergoing ENT surgery for benign lesions of the larynx (n = 10) or the parotid glands (n = 5). All participants answered the DHI and VSS-SF and underwent CDP the day before, and at follow-up after surgery. The AC patients also graded their dizziness through the use of a Visual Analogue Scale (VAS). RESULTS: Preoperatively, cyst patients scored higher than controls on subjective symptoms (DHI, VSS-SF A and VSS-SF V) and had a lower score on postural sway (CDP). Symptom scores decreased after surgery; the cyst patients improved in the subjective tests (DHI, VAS and VSS-SF), and three of the patients improved their CDP scores. In the controls, symptom and CDP scores were unchanged after surgery. CONCLUSION: Patients with fossa posterior cyst had a significant preoperative impairment compared with the controls, and they exhibited post-operative improvement in their subjective dizziness.

Pre- and post-operative dizziness and postural instability in temporal arachnoid cyst patients.

OBJECTIVES: Arachnoid cysts (AC) are benign, congenital malformations of the leptomeninges, with a predilection for the temporal fossa. In our clinical experience, patients with temporal AC often complain of dizziness and imbalance. However, these symptoms and the effect of surgery on them have not been studied before. MATERIALS AND METHODS: Dizziness and imbalance in patients with temporal AC were quantified before and after surgical cyst decompression, using the Dizziness Handicap Inventory (DHI), Vertigo Symptom Scale - Short-Form (VSS-SF) and computerized dynamic posturography (CDP). The study includes 16 patients with temporal AC and 15 control subjects undergoing surgery for benign lesions of the larynx (n = 10) or the parotid glands (n = 5). All participants answered the DHI and VSS-SF and underwent CDP the day before and 3-6 months after surgery. The patients with AC also graded their dizziness through the use of a visual analogue scale (VAS). RESULTS: Preoperatively, cyst patients scored higher than controls on subjective symptoms (DHI, VSS-SF A and VSS-SF V), but not on postural sway (CDP). Symptom scores decreased after surgery; the cyst patients improved significantly in the subjective tests (DHI, VAS and VSS-SF), while CDP scores did not. In the controls, symptom and CDP scores were unchanged after surgery. CONCLUSIONS: Patients with temporal AC have a significant preoperative impairment and post-operative improvement in their subjective dizziness, but not in postural sway as measured by CDP.

How often do chronic extra-cerebral haematomas occur in patients with intracranial arachnoid cysts?

BACKGROUND: Chronic subdural (CSDH) or intracystic haematomas may occur as a complication in patients with arachnoid cysts, even in children and young adults. The aim of this study was to investigate how often an arachnoid cyst is complicated by such haematomas, as this information may be of importance when considering decompressive cyst surgery. MATERIALS AND METHODS: This study includes a total of 241 consecutive, adult and paediatric patients (157 males and 84 females), that were referred to our department for treatment for an arachnoid cyst during the period January 1987-September 2004. Our department is the only neurosurgical department in a well-defined geographical region, with a population of 930,000. RESULTS: A chronic haematoma was found in a total of 11 patients (4.6%), all harbouring a temporal cyst. For the temporal cysts, the haematoma frequency was 6.5%. Haematomas occurred equally frequently in individuals with small, middle-sized and large temporal cysts, and in the age groups studied and in both genders. CONCLUSION: As also reflected in a literature review, intracranial chronic haematomas occur most frequently as a complication of middle fossa cysts. Possible mechanisms behind the formation of haematomas, and the strong associations with temporal fossa cysts, are discussed, with emphasis on the loose attachment of the membrane of the arachnoid cyst to the dura in the middle fossa, and its possible role as an "extra wall" covering easy-bleeding vascular structures in the dura.