*** RECOMMENDED
Trauma, genes and seizures
It has long been known that the development
of epilepsy from acquired pathology is loaded by genetic factors.
Those with head injuries or brain tumours are more likely to develop
seizures if they have a family history of epilepsy. This study gives
one potential genetic mechanism for a genetic-environment interaction.
The authors followed up 204 patients admitted to a neurosurgical
unit in Texas with severe head injuries as defined by depressed
skull fracture, intracranial injury on CT scan or early post-traumatic
seizures. Of these, only 106 were actually followed up. Those lost
to follow up had slightly milder injuries. 21/106 suffered post-traumatic
seizures and the relative risk of those with APOE e4 was 2.41 (range
1.15-5.07, P=0.03). APOE e4 is of course also implicated in Alzheimer’s
disease, which may be triggered by trauma and in the prognosis of
head trauma itself. The protein is the major lipid carrier in the
brain and is upregulated after injury. Its role in the development
of epilepsy is unclear but these data provide preliminary evidence
of its importance in another aspect of the response to injury. -MRAM
Diaz-Arrastia R, Gong Y, Fair S, Scott KD,
Garcia MC, Carlile MC, Agostini MA, Van Ness PC.
Increased risk of late posttraumatic seizures associated with inheritance
of APOE e4 allele.
ARCHIVES OF NEUROLOGY
2003;60:818-22.
PARKINSON’S DISEASE
*** RECOMMENDED
Long term benefits of deep brain stimulation for Parkinson’s
Over 500 studies of surgery for Parkinson’s
disease (PD) have been published since 1990, including over 10 000
patients. This indicates that surgery for PD has come of age spurred
on by neuroradiological, electronic and neurosurgical advances.
But studies of good quality with long term follow up are yet to
be published. Concerns that the immediate benefits of bilateral
deep brain stimulation of the subthalamic nucleus may not be long
lasting have been addressed by the pioneering group from Grenoble
who have reported their long term (5 years) observations in their
first 49 patients to receive such surgical intervention. This prospective
study assessed patients at baseline (prior to implantation of electrodes),
one, three and five years on and off medication. Patients had advanced
PD (duration of disease 14,6+/- 5 years), with severe levodopa related
motor complications.
The levodopa responsive motor elements tested when
off levodopa medication improved by 54% (p<0.001) and activities
for daily living improved by 49% (p<0.001) at 5 years compared
to baseline. This effect was sustained from early observations.
Levodopa-induced dyskinesia was reduced compared to baseline and
this effect was similarly maintained at 5 years. Speech was not
affected and a number of motor symptoms remained resistant to stimulation
(postural instability, freezing of gait, and akinesia). Overall
cognition was not affected but three patients had developed dementia
by 5 years. One patient had a large intracerebral haemorrhage and
one patient committed suicide. Apathy, hypomania, and depression
developed in a number of patients with some of these adverse events
being amenable to medication. An interesting early observation was
the gain of weight in most (n=41) patients probably as a result
of the decreased dyskinetic activity. However this study was not
a controlled study (admittedly difficult with such a surgical procedure).
The inclusion of suitable patients in the PD-Surg trial, which is
a large pragmatic controlled trial, should be considered in an attempt
to assess the longer term effects of surgery on patient rated quality
of life and cost effectiveness. This study does however go a long
way to reassure about maintained effect of this expensive treatment
option.
Krack P, Batir A, Van Blercom N, Chabardes
S, Fraix V, Ardouin C, Koudsie A,
Limousin PD, Benazzouz A, LeBas JF, Benabid AL, Pollak P.
Long term effects of bilateral stimulation of the subthalamic Nucleus
in advanced Parkinson's disease
NEW ENGLAND JOURNAL OF MEDICINE
349;20;1925-34
Stowe RL, Wheatley K, Clarke CE, Ives NJ, Hills
RK, Williams AC, Daniels JP, Gray R. Surgery for Parkinson's disease:
lack of reliable clinical trial evidence.
JOURNAL NEUROLOGY NEUROSURGERY PSYCHIATRY
2003;74:519-21.
