Review of PDS Tissue Bank Donor Profiles to June 2004

When a brain donation is made to the Tissue Bank, viewing brain cells stained using special methods down the microscope allows a pathological diagnosis to be made. An essential task in achieving the fullest possible understanding of the changes seen in the nervous system is to review all available clinical information, mainly by studying GP notes and copies of specialist letters. This dual process permits the optimum characterisation of the brain in the so-called 'clinicopathological correlation'.

Analysis of the medical notes of fifty-one tissue donations to the newly established PDS Tissue Bank has revealed a clinical diagnosis of Parkinson’s disease (PD) in 92% (47/51) of donations, a ‘Parkinson’s Plus’ syndrome, Multiple System Atrophy (MSA), in 6% (3/51) and Dementia with features of PD in one individual (2%). The average age at disease onset was 65 (range: 32-78) with the average age at death 77 (range: 42-87), thus yielding an average duration of illness of 12 years (range: 2-34 years). This confirms that with modern treatment regimens there is no significant shortening of the lifespan with PD. Approximately one third of the donors were female and the remaining two thirds male, which agrees well with the known gender ratio for PD. A predominantly tremulous presentation was found in 47% of donors with an akinetic-rigid syndrome (stiffness and slowness of movement without tremor) in 29%. Falls or ataxia (impaired walking) were dominant presenting features in 10% followed by autonomic nervous system dysfunction (mainly drooling) in 6% and dementia in one individual. In 6% (3/51) the mode of presentation remains unknown at this time.

Neuropsychiatric features were prominent, including hallucinations and delusions (59%), cognitive decline and dementia (61%), confusion and agitation (53%), depression (37%) and anxiety (27%). Autonomic nervous system dysfunction was also common, including bowel symptoms (mainly constipation) in 73%, bladder dysfunction (51%), speech and swallowing difficulties (53%), blood pressure abnormalities (37%), drooling (33%), sleep disorders (14%), sexual dysfunction (14%) and a seborrheoic skin rash and sweating (12%). These features relate both to PD itself as well as to the side effects of drug treatment.

Atypical or unusual features were found in several individuals, including abnormal eye movements in three, focal dystonia (abnormal limb posturing) on presentation in two, prominent drooling on presentation in five, myoclonus (jerky limb movements) in two and hand/wrist contractures (fixed abnormal posturing) in one case.

As further donations accumulate it will be possible to analyse these clinical features in more detail, with comparisons of the clinical course for disease onset at varying ages, assessments of the effects of differing drug treatment regimens, the influence of family history and other factors. A standardised collection of clinical data is planned with a prospective questionnaire to be sent out to all registered donors. This will increase the reliability and detail of the clinical histories, all of which will eventually be joined with detailed neuropathological diagnostic assessments. Combining examination of the clinical history with tissue analysis will produce clues regarding potential protective and aggravating environmental, treatment and familial factors as well and will help to indicate the brain regions responsible for specific signs and symptoms.

Tissue Bank Update

As the graphs show, up until the end of August 2004, the Tissue Bank has had just under 900 requests for information, of which 581 had then gone on to register with us as prospective donors. Of those that have registered in the past couple of years, 36% are actually people that do not have Parkinson’s or a related disorder, which is vitally important for research and allows identification of differences between changes in the normal ageing and the Parkinson’s brain. To the end of August there have been 71 tissue donations, of which 3 have been from people without Parkinson’s.