Brain biopsy in dementia: clinical indications and diagnostic approach

Abstract

Brain biopsy may be performed to make a definitive diagnosis in patients with rapidly progressive dementia. To assess the value of this procedure, we previously studied 90 consecutive cerebral biopsies performed in the tertiary referral centre of the National Hospital for Neurology and Neurosurgery, Queen Square between 1989 and 2003 (6 biopsies/year). Fifty-seven percent of all biopsies were diagnostic with Alzheimer's disease (18%), Creutzfeldt-Jakob disease (CJD) (12%) and inflammatory disorders (9%) being the most frequent. In the non-diagnostic group and for the series as a whole non-specific gliosis was the commonest diagnosis (37%). Treatment was altered because of information obtained from neuropathological findings in 11% of cases. To identify changes in practice that may have occurred due to recent advances in clinical assessment and improved histopathological techniques, we performed a follow-up study of 19 brain biopsies (approximately 3 cases/year) carried out for a dementing illness in the same centre between 2004 and 2009. These data suggest that brain biopsy may be less frequently used to help clinical diagnosis whilst its diagnostic yield increased from 57 to 74%. The commonest diagnosis was CJD, mostly suspected during life. Amongst the diagnoses, there were two cases of vasculitis and two cases of primary neurodegenerative dementia. These data suggest that improved clinical selection criteria supported by advances in diagnostic testing may result in brain biopsy being less frequently required, although it may still provide useful diagnostic information in difficult cases. We propose algorithms to aid the clinician in selecting appropriate patients for a biopsy and the neuropathologist in assessing a biopsy specimen.

Cortical Brain Biopsy in Long-Term Prognostication of 468 Patients with Possible Normal Pressure Hydrocephalus

“…In addition, the biopsies can be used in the validation of less invasive markers and together with blood and cerebrospinal fluid samples may introduce new potential surrogate markers for AD. Brain biopsy may also help in the evaluation of for example ␣ -synuclein and TAR DNA-binding protein 43 pathologies, but there are only case reports of these patients with brain biopsy available [15] . Case series with systematic postmortem neuropathological confirmation would increase the value of brain biopsy in these diagnoses.…”

“…Brain biopsy has seldom been included in the diagnostics of dementia [14,15] due to fear of complications, the amount of neurosurgical resources needed and lack of disease-modifying therapies. Diagnostic workup and treatment of NPH enable to obtain brain biopsies.…”

Diagnosis and treatment of rapidly progressive dementias

“…Brain biopsies in dementia (not necessarily RPD) generally have had diagnostic yields of 20%-57%, finding treatable causes in about 10% of cases. 23,32 Schott et al 33 provide a pragmatic guide for physicians when brain biopsy in dementia is being considered.…”

Creutzfeldt-Jakob disease: updated diagnostic criteria, treatment algorithm, and the utility of brain biopsy

“…In a study of 90 patients with rapidly progressive dementia, Schott et al showed a 57% diagnostic rate, but only 11% of these diagnoses resulted in a change of treatment. 46 Some will argue that because a biopsy will provide no change in the treatment, it only is adding costs and wasting resources that can be used elsewhere. Figure 2 shows a recent trend in hospital costs associated with those undergoing a surgical procedure that provides no benefit.…”