Transient
hiccups after posteroventral pallidotomy
for
Parkinson's disease
RMA De Bi, JD Speelman et al.
Department of Neurology,
Academic Medical Center
University of Amsterdam, The
Netherlands
Hiccup is defined as an abrupt intermittent,
involuntary, contraction of the diaphragmatic
and external (inspiratory) intercostal muscles,
with inhibition of expiratory intercostal
activity. This results in a sudden inspiration,
abruptly opposed by closure of the glottis.1
Hiccup may result from various structural or
functional disorders of the medulla, the
afferent or efferent nerves to the respiratory
muscles, and the gastrointestinal tract.2 3
Newson Davis performed a study of hiccup with
electrophysiological techniques and concluded
that hiccup is served by a supraspinal mechanism
distinct from that generating rhythmic
breathing.3 The principal site of interaction of
the hiccup discharge with other descending
drives to the respiratory motoneuron is at the
spinal level. Neurogenic hiccup is particularly
associated with structural lesions of the
medulla oblongata.
Since 1994 we have performed 66
pallidotomies for Parkinson's disease in 60
patients. So far, we have seen transient hiccups
in seven patients after the operation (table).
Our target coordinates for the posteroventral
globus pallidus at the border of the medial and
lateral segments are 2&endash;3 mm anterior to
the midcommissural point, 5 mm below the
intercommisural line, and 22 mm lateral to the
midline of the third ventricle. Ventriculography
was performed for target localisation. Patients
started with a short schedule of corticosteroids
(5 days) the night before surgery. The hiccups
started immediately after the operation or the
next day, were intermittent, and the bouts of
hiccup of six patients, with a duration of
hours, resolved within 3 days after the
procedure. One patient complained of
yawning more often and frequent bouts of
hiccup for 6 months.
Five patients were men. All patients were
right handed. The mean age at surgery was 54
years and the mean duration of Parkinson's
disease was 12 years. All patients were taking
levodopa. In four patients the hiccups appeared
after a left sided pallidotomy. Patient 2 had a
right sided thalamotomy 4 years before the
pallidotomy. Patient 5 underwent a left sided
pallidotomy 10 months before the right sided
pallidotomy which caused the hiccups. The
pallidotomies improved parkinsonism in the "off"
state (table), contralateral dyskinesias, and
pain accompanying Parkinson's disease. Six
patients had transient adverse events: four
patients had a transient facial paresis
postoperatively and two a slight transient
dysarthria (table). Two patients had choreatic
movements after the pallidotomy at the
contralateral side which resolved spontaneously
within 2 hours and is associated with a
favourable surgical outcome.4
Postoperative MR scans were obtained in the
first six patients, and showed that in five
patients the lesions were located in the
posterior part of the globus pallidus pars
externa (GPe) and interna (figure). In patient 5
the lesion was situated slightly more anterior
in the GPe and putamen. In patient 3 there was a
small separate lesion more dorsal, probably an
infarct.
We never encountered hiccups in 150 other
stereotactic procedures for Parkinson's disease,
such as thalamotomies or deep brain stimulation
electrode implantation in the thalamus and
therefore it is unlikely that medication or
positive contrast medium ventriculography with
Iohexol evoked the hiccups.
A possible cause for the transient hiccups
could be the lesion in the ventral medial
segment of the globus pallidus or pressure, due
to oedema, on an adjacent structure like the
internal capsule or putamen. We could not find
other reports of hiccups as an adverse event
after functional stereotactic surgical
interventions, nor after lesions of other
aetiology involving the striatium.5 Based on our
experience we hypothesise that the globus
pallidus or a neighbouring structure may be
involved in a supramedullary system involved in
triggering hiccups.
RMA DE BI, JD SPEELMAN
Department of
Neurology
PR SCHUURMAN, DA BOSCH
Department of Neurosurgery, Academic Medical
Center, University of Amsterdam, The
Netherlands
Newson Davis J. An experimental study of
hiccup. Brain 1970;93:851&endash;72.
Howard RS. Persistent hiccups. British
Medical Journal 1992;305:1237&endash;8.
Newson Davis J. Pathological interoseptive
responses in respiratory muscles and the
mechanismof hiccup. In: Desmedt J, ed. New
developments in electromyography and clinical
neurophysiology.Vol 3. Basel: Karger,
1973:751&endash;60.
Merrello M, Cammarota A, Betti O, et al.
Involuntary movements during thermolesion
predict a better outcome after microelectrode
guided posteroventral pallidotomy. J Neurol
Neurosurg Psychiatry 1997;63:210&endash;13
Bathia KP, Marsden CD. The behavioral and
motor consequences of focal lesions of thebasal
ganglia in man. Brain
1994;117:859&endash;76
Pallidotomy
Until the late 1990s, pallidotomy was the
most common type of PD surgery; deep brain
stimulation or DBS is now being performed more
often. A pallidotomy involves destruction of
part of the globus pallidus (GPi), a region of
the brain involved with the control of movement.
Destroying part of the GPi may help to restore
the balance in that area of brain, which normal
movement requires. Pallidotomy is performed by
insertion of a wire probe into the GPi.
Once its placement has been confirmed by
electrical tests, the probe heats surrounding
tissue by emission of radio waves. The heat
destroys nearby tissue. Effects of the surgery
are apparent almost immediately. Improvements
from pallidotomy range from 70% to 90% reduction
of dyskinesias and dystonia, and 25% to 50% for
tremor, rigidity, bradykinesia, and gait
disturbance. Levodopa dose may be reduced after
the surgery, and dyskinesia improvement is based
partly on this reduction.
Pallidotomy may be unilateral (one-sided) or
bilateral (two-sided). Following a unilateral
pallidotomy, improvements are primarily to the
side of the body opposite to the lesioned side
of the brain. Bilateral surgery is possible and
improves dyskinesias further, but greatly
increases the risk for worsening effects on
cognition, swallowing, and speech; hence, it is
done very rarely if at all.
Adverse effects of pallidotomy may include
hemorrhage, weakness, visual deficits, speech
deficits, and confusion, but the risk of these
is relatively low in centers with an experienced
surgical team. Weight gain is very common
following surgery
