AN INTRACRANIAL ARTERIOVENOUS MALFORMATIONAND PALATAL MYOCLONUS RELATED
TO PSEUDOXANTHOMA ELASTICUM

J. B. CHALK
Neurology Registrar, Department of Medicine, University of Queensland and Department of Neurology. Royal Brisbane Hospital, Qld

M. C. PATTERSON
Pediatric Neurology Registrar, Royal Children’s Hospital, Old

M. P. PENDER
Senior Lecturer, Department of Medicine, University of Queensland and Department of Neurology, Royal Brisbane Hospital, Qld

Abstract:
Pseudoxanthoma elasticum is a rare hereditary disorder of elastic tissue with central nervous
system manifestations due to occlusive vascular disease and aneurysm formation. Here we report
the first recorded case of an intracranial arteriovenous malformation (AVM) in a patient with
pseudoxanthoma elasticum. The AVM, which was located in the pons, also had an unusual
manifestation, namely palatal myoclonus. (Aust NZ J Med 1989; 19: 141-143.)
Key wonls: Pseudoxanthoma elasticum, palatal myoclonus, arteriovenous malformation.

Pseudoxanthoma elasticum (PXE) is a rare hereditary
disorder of elastic tissue with protean manifestations
including characteristicyellow papular skin lesions, retinal
angioid streaks, and occlusive vascular disease. The
reported neurological manifestations of PXE are cerebral
infarction due to progressive vascular disease and
subarachnoid hemorrhage due to aneurysm formation.’,’
Here we report the occurrence of an intracranial AVM
and palatal myoclonus in a patient with PXE.

CASE REPORT
A 38-year-old female presented in 1987 with severe right sided
headache, neck pain and photophobia. A dermatologist
diagnosed PXE in 1962. In 1976 tingling suddenly developed in
her left hand and over subsequent hours her left arm became
numb, and she had difficulty using it. She also complained of
being unsteady on her feet. Neurological examination in 1976
revealed horizontal and vertical nystagmus, reduced touch
sensation in the left upper limb and ataxia of the right hand and
left leg. A radionuclide brain scan, visual evoked potentials, and
cerebrospinal fluid examination were normal. In 1977 she had
a constant right sided headache and later that year had a severe
right sided headache requiring admission to hospital. The
numbness in her left upper limb had remained. She now had

intermittent claudication in both legs. Examination revealed neck
stiffness, angioid streaks, a right partial internuclear
ophthalmoplegia, a right Horner’s syndrome, a positive
Romberg’s sign, and unsteadiness on tandem gait. A lumbar
puncture showed uniformly blood-stained CSF. A vertebral
angiogram demonstrated a pontine AVM (Figure 1) supplied by
the right posterior cerebral artery, with a dilated vein draining
into the great vein of Galen. The AVM was considered
inoperable. In 1981 she had increasing difficulty with walking
and clumsiness of her left arm, diplopia on looking to the left,
and persistent right sided headache. Neurological examination
showed a right partial internuclear ophthalmoplegia, upbeat
nystagmus on upgaze, and right horizontal gaze-evoked
nystagmus. There was a reduction in palatal elevation, weakness
of left finger extension and ataxia in the left forearm and right
leg. Light touch sensation was reduced in the left hand. The
tendon reflexes were depressed and the plantar responses were
flexor. Her gait was wide-based. In 1983 her problems were
dysarthria, and increasing difficulty with walking with several
falls. Neurological examination showed intention tremor in all
limbs, dysarthria and other signs as listed above. She had a course
of radiotherapy to the intracranial AVM in 1983. In 1984 she
had episodic severe headaches which required admission to
hospital on three occasions.
On examination in 1987 yellow papules measuring 3 mm in
diameter and redundant skin folds were noted over the neck,

Reprint requests to: Dr J. Chalk, Department of Medicine, University of Queensland, Clinical Sciences Building, Royal Brisbane
Hospital, Bowen Bridge Road, Herston 4029, Brisbane, Australia.
PXE WITH AN AVM AND PALATAL MYOCLONUS

Aust NZ J Med 1989; 19

141

Figure I (A): Left vertebral angiogram showing arteriovenous malformation in anteroposterior view, Figure 1 (B): Left vertebral
angiogram showing arteriovenous malformation in lateral view.

axillae and antecubital fossae. Titubation ofthe head was present.
Her corrected visual acuity was 6/18 in the left eye and 6/12
in the right. Fundoscopy revealed normal optic discs, bilateral
angioid streaks and hemorrhage at the left macula. There was
a complex disorder of eye movements with a right internuclear
ophthalmoplegia and disconjugate nystagmus with horizontal
and vertical components. Light touch and pain sensation were
reduced on the left side of the face. Examination of the mouth
and neck showed bilateral palatal weakness with a normal gag
reflex, palatal myoclonus at 2 HZ with slight deviation to the
right, dysarthria, and involuntary vertical movements of the
thyroid cartilage also at 2 Hz-The tone, Power and d*P tendon
reflexes were equal and normal and the plantar responses were
flexor, postural instability, ataxia and dysdiadwhokhesis of both
upper limbs (worse on the left), involuntary movements of the
left upper limb, and severe ataxia on heel-knee-shin testing were
also present. She was unable to walk without support because
of severe gait ataxia. Light touch sensation was reduced in the
left arm. Head CT showed punctate calcification in the pontine
region anterior to the fourth ventricle (Fig. 2A). Following
contrast the region anterior to the fourth ventricle enhanced
significantly (Fig. 2B and 2C). The cerebrospinal fluid was
uniformly blood-stained. Polygraphic recordings demonstrated
that the laryngeal and vertical eye movements were synchronous.
Skin biopsy and review by a dermatologist confirmed pseudoxanthoma elasticum. The palatal myoclonus did not respond to
carbamazepine, clonazepam or sodium valproate.

DISCUSSION
PXE is a rare inherited disorder of elastic tissue with
diverse manifestations including angioid streaks, retinal
disease of the limbs
hemorrhage and scarring,
with claudication and diminished pulses, skin involvement
with small yellow papules and redundant skin folds in
the neck, axillae and groins, cardiac involvement and
gastrointestinal hemorrhage.’ Reported neurological
manifestations include subarachnoid hemorrhage,’

142

multiple cerebral infarcts due to atheromatous changes
in large a d
arteries,’ carotid artery aneurysm,4and
anterior spinal artery aneurysm.^
This is the first reported case of an intracranial AVM
in pXE-The wntine AVM had an unusual manifestation,
namely Palatal mYocfonus. Palatal mYOClOnuS and the
associated involuntary movements involving the ocular,
pharyngeal, laryngeal, diaphragmatic and limb muscles
are due to a lesion of the pathway from the dentate
nucleus through the superior cerebellar peduncle to the
central tegmental tract and contralateral inferior olive.6.7
brain Stem
Causes Of Palatd myoc1onus
infarction,’-” multiple
head trauma,8,9
Meige’s Syndrome,* turnours
cerebellar
astrocfloma,’ cerebellar degeneration,’ spinocerebellar
degeneration,” Behcet’s disease,lL and possibly
radiotherapy.l*
We suggest that the palatal myoclonus in our patient
is due to involvement of the central tegmenhl tracts by
the pontine AVM. The pontineAVM also accounts for
the other neurological signs. It is unclear whether the
radiotherapy contributed to the
Of the
palata1 myoclonus by
the pontine vasculature.
The defect in elastic tissue in PXE may have predisposed
to the development of the AVM.
Acknowledgements:
We are grateful to Dr K. Grossart of the Institute of Neurological
Sciences, Glasgow and Dr G. Glasgow of Auckland Hospital,
Auckland for allowing us
to their
records and
permission to publish angiograms,

Accepted for publication: 18 August 1988

Aust NZ J Med 1989; 19

CHALK ET AL.

References
1. Goodman RM, Smith EW, Paton D, et ul. Pseudoxanthoma
elasticum: a clinical and histopathological study. Medicine
1963; 42: 297-334.
2. Sharma NG, Ghosh SK, Beohar P C , Gupta PS.

Subarachnoid hemorrhage in pseudoxanthoma elasticum.
Postgrad Med J 1974; 50: 774-6.
3. Fasshauer K, Reimers CD, Gnau H J , Strempel I, Rossberg
C. Neurological complications of Gronblad-Strandberg
syndrome. J Neurol 1984; 231: 250-2.
4. Munyer T P , Margulis AR. Pseudoxanthoma elasticum with
internal carotid artery aneurysm. AJR 1981; 136: 1023-4.
5. Kito K, Kobayashi N, Mori N, Kohno H. Ruptured
aneurysm of the anterior spinal artery associated with
pseudoxanthoma elasticum. Case Report. J Neurosurg 1983;
58: 126-8.
6. Guillain G. The syndrome of synchronous and rhythmic

palato-pharyngo-laryngo-oculo-diaphragmatic
myoclonus.
Proc R SOCMed 1938; 31: 1031-8.
7. Lapresle J, Hamida MB. The dentato-olivary pathway.
Somatotopic relationship between the dentate nucleus and
the contralateral inferior olive. Arch Neurol 1970; 22:

Figure 2 (A): C T without contrast, showing punctate
calcification (arrow) in the region anterior t o the fourth
ventricle. Figure 2 (B): C T with contrast, showing
enhancement in the region of the pons. Figure 2 (C): CT
with contrast, showing dilated vessels draining the AVM.
PXE WITH AN AVM AND PALATAL MYOCLONUS

135-43.
8. Jankovic J, Pardo R. Segmental myoclonus. Clinical and
pharmacologic study. Arch Neurol 1986; 43: 1025-31.
9. Westmoreland BF, Sharbrough FW, Stockard JJ, Dale AJD.
Brainstem auditory evoked potentials in 20 patients with
palatal myoclonus. Arch Neurol 1983; 40: 155-8.
10. Nakada T, Kwee IL. Oculopalatal myoclonus. Brain 1986;
109: 431-41.
11. Nagaoka M , Narabayashi H. Palatal myoclonus - its
remote influence. J Neurol Neurosurg Psychiatry 1984; 47:
921-6.
12. Jabbari B, Gunderson C H . Palatal myoclonus responding
to trihexyphenidyl. Ann Neurol 1983; 14: 95.

Aust N Z J Med 1989; 19

143