Posteroventral pallidotomy in Parkinson's disease

We analyse the clinical aspects, results and reliability of posteroventral pallidotomy (PVP) carried out as treatment for the principal symptoms and treatment induced complications in patients with Parkinson's disease (PD).

Between August 1995 January 1998, 17 patients with PD were treated surgically, 13 patients with PVP. A pre- and post-surgical clinical evaluation was carried out. Riechert's Stereotactic System (MHT, Freiburg, Germany) was used. Ventriculography under stereotactic conditions was used in the PVP procedures, Laitinen's co-ordinates as anatomical target, and electrical stimulation for physiological determination. 3 4 radiofrequency lesions were made at 83 degrees C for 20". The mean age was 60 +/- 10.8 years, ages ranging from 45-79 years. 8 (60.5%) of the patients were male. The cardinal symptoms of the series were bradykinesia and rigidity. The duration of the illness ranged from 8.6 +/- 3.7 years with a range of 4-15 years. 7 (53.8%) presented with a duration of 10 years or more. 6 (46,2%) of the patients underwent left PVP, the remaining 7 (53.8%) right PVP. Only one patient received treatment with right PVP and ipsilateral thalamotomy in the same surgical procedure. The mean post-surgical follow up was 16 +/- 7 months, with a range of 2 to 26 months.

An up to date evaluation was carried out on all patients showing significant changes after PVP in UPDRS motor (P < 0.005), complete rigidity relief (P < 0.005), bradykinesia relief (P < 0.005) and complete tremor relief (P < 0.005). An important improvement in contralateral dyskinesia was noted after PVP. A subjective evaluation of the results showed excellent results in 4 (30.8%) patients, good in 6 (46.2%) and fair in 3 (23%). No significant correlation was found between age and duration of illness (P = 0.7). Two patients suffered slight side effects, one patient with worsening of hypophonia whilst the other suffered subjective visual impairment controlled by normal post operative ophthalmological examinations. There was no peri-operative mortality.

PVP is considered a safe and effective surgical method for the treatment of both the principal symptoms of PD and the complications of DOPA medication.