DR Medhat MRCP

سؤال امتحان Trigeminal neuralgia
A severe unilateral paroxysmal electric shock-like facial pain < 2min.
Often described by patients as the "the world's worst pain."
French term "tic doloreux" describes the suddenness of the pain that
may be triggered by touch (washing,shaving) , cold , chewing,smooking
or brushing teeth.
More common in females (200/100,000 women)
Onset is usually uprupt in the sixth or seventh decade of life
Aetiology : Most common is idiopathic.
Vascular compression of trigeminal roots.
M.S or compression by tumor (minority of cases)
Treatment : Carbamazipine (Tegretol) is the 1 st line.
Prognosis : poor.
V. Abducens nerve :
- The nucleus of this nerve lies in the floor of 4 th vent/ upper part of the pons.
- The nerve runs along the intracranial course to supply lateral rectus ms
which moves the eye outwards(laterally)
• Lesion :
Diplopia : only on looking outwards towards the paralysed side.
Limitation of movement of the affected eye on looking outwards.
The pupil
- The size of the pupil is affected by 2 groups of smooth muscles acting on the iris :
Constrictor pupillae muscle : dominant , receive parasympathetic supply from
occulomotor nerve reaching it via short ciliary nerves.
Dilator pupillae muscle : which receive sympathetic supply via long ciliary
nerves .
- Pathway of sympathetic supply :
Hypothalamus descend through brain stem & spinal cord LHC of C8-T1
preganglionic fibers in anterior roots of C8-T1 cervical sympathetic chain
relay in superior cervical ganglion postganglionic fibers ascend arrond
internal carotid arteryto enter the ceanial cavity to supply the following
through long ciliary nerves : 1. Dilator papillae muscle.
2. Smooth ms of upper eyelid ( 30% of elevation)
3. Vasocostrictor fibers to eye & face.
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