The patient is a 59-year-old man diagnosed with PD at the age of 49 years.
Fluctuations with recurring “off” states and peak dose dyskinesias had severely diminished the patient’s quality of life.
Thus, the patient was deemed a candidate for bilateral subthalamic DBS.
Multidisciplinary evaluation with 75 % positive response in the standardized levodopa test, exclusion of cognitive decline or psychiatric comorbitity, and absence of structural brain damage potentially relevant to the lead placement led to the unanimous decision for DBS placement.
When decision was made to proceed to surgery the medication consisted of 1112.5 mg of levodopa and 150 mg of piribedil.
There was no history of orofacial or cervical dystonia.
In the “on” state the patient was alert without any signs of psychiatric comorbidity.
Neuropsychological testing was adequate.
No cranial nerve deficits were found and swallowing was normal.
Gait and postural stability was normal with minimal rigidity in the neck and right arm.
Coordinative motor skills such as rapid pro- and supination were restricted in the left hand.
Dyskinesias were evident with moderate impairment.
In the “off” state after the medication was held for 12 h, the patient showed mild dysarthria and dysphonia, resting tremor of the right arm and leg, as well as slight action tremor in the right hand.
Rigidity was severe in the neck, marked in the right, and mild on the left side.
Motor skills of the hands were markedly impaired.
Gait was slow but unaided and comprised of by intermittent freezing; there was mild dystonic posturing of the right foot.
There were no signs of laryngeal spasms, however.
On the day before surgery, the last dose of dopaminergic medication was administered at 07:00 p.m., the bedtime dose of levodopa was held to facilitate intraoperative testing.
On the day of the operation, the patient underwent placement of the stereotactic frame under local anaesthesia around 09:00 a.m.
After planning standard STN coordinates and trajectories, the patient was placed in a semi-sitting position on the O.R.
table, with the frame attached to the table.
At the patient’s request, the head was slightly flexed anteriorly for comfort.
The left electrode was placed uneventfully.
When performing the bur hole on the right side, the patient complained of cramping in the neck and facial muscles as well as difficulties breathing although at that point, pulse oximetry showed good saturation readings at ≥95 %.
He progressed to dystonic dysarthria [6].
Microelectrode recordings had already been done and macroelectrode test stimulation was about to begin, when the patient showed high-pitched inspiratory stridor.
Pulse oximetry showed decreasing oxygen saturation at 02:15 p.m.
and, shortly thereafter, narrow complex tachycardia was noted.
Within a minute, the patient became unresponsive.
Cardiac resuscitation was initiated and the patient was fiberoptically intubated after removal of the front bar of the stereotactic frame.
During fiberoptic intubation laryngeal spasm was confirmed visually.
A transthoracic echocardiogram obtained immediately after successful resuscitation showed no cardiac pathology or any air bubbles.
Stimulation using the implanted lead to resolve the symptoms was not possible as at that time the lead was subcutaneously tunnelled with no impulse generator attached.
The right permanent electrode was placed without further testing according to microelectrode recordings.
50 mg levodopa was administered over a nasogastric tube every two hours during the subsequent postoperative period.
Postoperative head CT scan done immediately after the procedure was normal.
The patient was transferred to the intensive care unit and was extubated at 02:00 p.m.
the following day without any neurological deficit or signs of laryngeal spasms.
By then, the nasogastric tube was discontinued and the preoperative medication was resumed.
Cardiac workup was negative.
The impulse generator was implanted 7 days later and the patient showed good symptom control of PD.