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NEUROVASCULAR COMPRESSION |
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ENTITIES |
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Trigeminal
neuralgia Hemifacial
spasm Glossopharyngeal
neuralgia Arterial
hypertension Trigeminal
neuralgia Trigeminal
neuralgia is a facial pain with a very characteristic manifestation in the
region of supply of the fifth cranial
nerve (trigeminal nerve). Pain related to trigeminal neuralgia is located in
one or several branches of the nerve. The pain is classically described as
sharp, lancinating
and electrifying. Usually the pain is located only on one side, but in 5-6%
the pain occurs on both sides. The pain attacks last from seconds to minutes.
Some attacks persist for several days. Pain can be triggered by eating, laughing,
brushing teeth, talking, shaving, or touching the face. Occasional slight
numbness around the mouth can be present.
Microvascular
decompression introduced by Jannetta is the causal therapy with
the goal to remove surgically the neurovascular compression of the nerve. In
contrast to the other destructive methods, excellent long-term results
concerning freedom from pain, preservation of function and quality of life
can be expected. Hemifacial spasm Hemifacial spasm is a rare
condition of the facial nerve (cranial nerve VII). It presents as
uncontrollable half sided contractions of the mimic facial muscles around the
mouth and eye which are called synkenisia. The contractions can be twitches
or lasting tonic cramps which entirely distort one side of the face. Usually
hemifacial spasm is not painful. The affected person suffers mainly from a
loss of social status and integration (i.e. setback in career, isolation). Tumors along the facial nerve,
inflammatory changes or injuries to the nerve as well as pathologic changes
of the brain stem can be causes of hemifacial spasm in rare cases. In most
cases we find a neurovascular
compression of the nerve at its root entry zone in the
posterior cranial fossa. MRI is the diagnostic procedure of choice. A
high-resolution MRI together wit 3D-image processing can detect a
neurovascular compression. Medical treatment of hemifacial
spasm includes carbamazepine, phenytoin, and Baclofen, but is not very
effective. Injections of botulinum toxin in the affected facial muscle
causing a temporary paralysis of the corresponding muscles serve as
symptomatic trearment. The effect usually subsides after a certain period of
time and the symptoms return. Repetition of this procedure can result in
permanent weakness of the affected muscles or antibodies against botox
develop, which reduce the effectiveness dramatically. Microvascular
decompression is the causal therapy for the
neurovascular compression in hemifacial spasm. In 80-90% of the cases this
procedure results in permanent success without a loss of functionality.
Destructive methods such as severing the nerve causing functional disorder
should be avoided. Glossopharyngeal
neuralgia Glossopharyngeal
neuralgia (GN) is a pain that occurs in the pharynx, tongue and lingual base
and can also reach the external auditory canal in extreme cases. The pain is
described as sharp, shooting, lancinating and electrifying. It can sometimes
have "destructive" characteristics. The pain can occur
spontaneously or at the onset of swallowing, talking, coughing or touching
the tongue or throat. Arrhythmia can occur during some pain attacks.
Left-sided glossopharyngeal neuralgia can also be conjunct with arterial
hypertension. In rare
cases GN is associated with tumors along the nerves or the neck, inflammatory
alterations of the nervous system or damage to the nerve itself. In most
cases no clear cause can be detected and these are then classified as idiopathic
glossopharyngeal neuralgia. In most instances, this form displays a vascular
loop at the root entry/exit zone of the cranial nerve IX & X leading to a
neurovascular compression. Neurovascular compression can be identified
regularly by high resolution MRI. Carbamazepine,
phenytoin and gabapenthine are used for medical treatment. Apart from that,
various methods concerning the infiltration of anaesthetics or alcohol at
different extra cranial locations along the nerve are performed and mainly
result in a partial relief of pain. Microvascular
decompression has resulted into high rates of success with permanent pain
relief without loss of function. This method is increasingly being recognized
as the best way to treat this entity. Destructive techniques such as severing
the nerve are not recommendable. Arterial
hypertension High blood
pressure is prevalent in about 10% of the population. Over 80% of these
patients suffer from the so-called essential hypertension, having no clear
etiology of their disease.
Longstanding hypertension causes arteriosclerosis, stroke and heart
attack. Therefore many patients depend on live long medication. It is
known that the central nervous system plays a major role in regulating the
blood pressure. Newest findings frequently show in patients with arterial
hypertension contacts between vessels and cranial nerves IX & X like
neurovascular compression at the ventrolateral medulla. These
contacts were removed in a certain number of patients - microvascular decompression
- and led not only to a lowering of the blood pressure but also in some cases
to complete normalization. We can therefore assume a association between
neurovascular compression and the essential hypertension. This
association is being investigated in a cooperative scientific study of the
department of neurosurgery and the medical clinic IV - nephrology of the
University Erlangen-Nuremberg. A neurovascular compression at the brain stem
in arterial hypertension can be easily proven by high resolution MRI. In
selected cases resistant to medical therapy microvascular compression can be
taken into consideration. |
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NVCHOME.COM |
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R. NARAGHI |
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