Trigeminal neuralgiaTrigeminal neur

Trigeminal neuralgia
Trigeminal neuralgia (TN) is
defined by the International Association
for the Study of Pain (ISAP) as a
‘sudden and usually unilateral severe
brief stabbing recurrent pain in the
distribution of one or more branches of
the fifth cranial nerve’.16 Idiopathic and
secondary forms are recognized and
conditions such as multiple sclerosis,
benign or malignant lesions being
contributory factors. Categorization of
TN into classical and atypical forms is
based on symptoms and not aetiology.17
TN is being increasingly recognized
with its annual incidence now being
estimated around 12.8 per 100,000,
with a peak incidence in 50–60-yearolds.
TN symptoms arising in younger
patients should alert the clinician to the
possibility of an underlying cause, such
as multiple sclerosis.
Classical TN presents with
shooting, sharp, unbearable pain in the
distribution of one or more branches
of the trigeminal nerve, of moderate
to intense severity, lasting seconds.17,18
The right side of the face is affected in
60% of sufferers, it is unilateral in 97%
of cases and rarely in first division only.
It is precipitated by light touch, but may
be spontaneous, and there are often
associated trigger points. Patients may
have periods of remission lasting days,
weeks or longer.
Glossopharyngeal neuralgia (GPN)
Defined by the IASP as sudden
severe recurrent pain in the distribution
of the glossopharyngeal nerve, GPN is
very rare, with an incidence of 0.7 per
100,000, and is more common in females
and those aged over 50 years.19 Classic
and secondary forms are recognized.
Classic GPN is severe recurrent stabbing
pain in the ear, base of tongue, tonsillar
fossa or below the angle of the mandible.
It is precipitated by swallowing, talking or
coughing.
Secondary GPN presents
with an additional ache that may persist
between attacks and is secondary
to a cranial lesion demonstrable by
investigations or surgery. The pain is
unilateral in location and there are no
obvious motor neurological defects.
Episodes of pain may last from weeks to
months.
Although also rare, a
syndrome known as Eagles syndrome
should be considered in patients
presenting with classical symptoms
of GPN. Eagles syndrome describes
symptoms related to an elongated
styloid process impinging on adjacent
anatomical structures and is associated
with pain and dysphagia on chewing and
on turning the head to the affected side.