Case Reports / Journal of Clinical Neuroscience 20 (2013) 757–759

757

Symptomatic palatal tremor of cortical origin due to stroke
Richard Salazar ⇑, Daniel Miller
Department of Neurology, Henry Ford Hospital, 2799 West Grand Boulevard, Detroit, MI 48202, USA

a r t i c l e

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Article history:
Received 9 May 2012
Accepted 12 May 2012

Keywords:
Palatal myoclonus
Stroke
Symptomatic palatal tremor

a b s t r a c t
Palatal tremor (PT) is usually considered a movement disorder that presents with recurring rhythmic
contractions of the soft palate. The inferior olive shows a characteristic pseudohypertrophy secondary
to brainstem lesions in the triangle of Mollaret and Guillain that interrupt dentato-olivary and tegmental
pathways. We report a 35-year-old man with a history of uncontrolled hypertension who presented to
the emergency department with PT after a left middle cerebral artery ischemic stroke. The diagnostic
work-up consisted of brain MRI, which revealed restricted diffusion over the left frontoparietal lobes
without involvement of the brainstem. During hospitalization, the patient reported two brief episodes
of soft palate and base-of-the-tongue high-frequency, low-amplitude and rhythmic tremor that resolved
after intravenous administration of lorazepam. A 2-hour video electroencephalogram showed no abnormalities. After initiation of levetiracetam therapy, no further spells were reported by the patient. At the 2month follow-up, the patient had had no episodes of stereotypical PT or upper limb tremors since discharge. This report provides further evidence of the central role of the cortex in the generation of PT.
The cortical origin of symptomatic palatal tremor (SPT) should be considered in patients presenting after
an acute ischemic insult, particularly if there is no evidence of a brainstem lesion. Potential causes of SPT
of cortical origin include focal epilepsy and diaschisis.
Ó 2012 Elsevier Ltd. All rights reserved.

1. Introduction
Palatal tremor (PT) is usually considered a movement disorder
that presents with recurring rhythmic contractions of the soft palate and sometimes synchronous twitching of the lower facial muscles, pharynx, larynx, trunk, and extremities. Recently the term
‘‘palatal tremor’’ was recommended in preference to ‘‘palatal
myoclonus’’. The inferior olive, which is considered the pacemaker
for PT, shows a characteristic pseudohypertrophy secondary to
brainstem lesions in the triangle of Mollaret and Guillain interrupting dentato-olivary and tegmental pathways. Reports of PT of cortical origin are rare.1,2

2. Case report
We report a 35-year-old man with history of uncontrolled
hypertension who presented to the emergency department after
sudden development of right hemiparesis, hemihypoesthesia, and
expressive aphasia. One week earlier, he had experienced similar
symptoms and had been diagnosed with a small left frontoparietal
ischemic stroke due to symptomatic distal left middle cerebral artery stenosis and had experienced an episode of right arm twitching believed to be epileptic.
Initial diagnostic work-up included MRI of the brain and MRA of
the head/neck. This confirmed a new acute ischemic infarct within
the territory of the superior division of the left middle cerebral artery (MCA) and did not involve the basal ganglia or brainstem
(Fig. 1). During day 1 of admission, the patient had intermittent
and rhythmic right face and arm twitching without impairment
of consciousness. Empiric therapy with levetiracetam (500 mg
twice daily) was initiated without electrographic confirmation as
the patient refused to be tested at that time.
During hospitalization, the patient reported two brief episodes
of complete inability to speak and tremor of the floor of the mouth.
Examination during the first episode revealed soft palate and baseof-the-tongue high-frequency, low-amplitude and rhythmic tre⇑ Corresponding author. Tel.: +1 313 303 7863.
E-mail address: ricsalmont@hotmail.com (R. Salazar).

mor with subtle right eyebrow twitching and inability to speak
(Supplementary Video 1). Intravenous administration of 2 mg of
lorazepam stopped the involuntary movements. A 2-hour video
electroencephalogram showed broad left fronto-temporal and centro-parietal delta slow waves without epileptogenic activity. However, no clinical spells were captured during the recording.
After administration of lorazepam for the acute event, and
increasing the dose of levetiracetam to twice daily 1500 mg, no
further episodes of palatal tremor or unilateral face and arm
twitching occurred. In the meantime, review of the two prior
MRI showed no evidence of lesions within Mollaret’s triangle or
hypertrophy of the inferior olives. A repeat brain MRI excluded
new lesions (Fig. 1D, E). A brain CT perfusion study demonstrated
decreased cerebral blood flow, decreased cerebral blood volume
with increased mean transit time restricted to the left frontoparietal lobes consistent with his known infarct. On discharge, the patient continued to show signs of clinical recovery without
recurrence of the PT. At the 2-month follow-up, the patient had
had no episodes of stereotypical PT or upper limb tremors since
discharge. Thus, the dose of levetiracetam remained unchanged;
however, a slow tapering schedule will be considered after a short
period of sustained remission.

3. Discussion
Palatal tremor (PT), earlier known as palatal myoclonus, is a
rhythmic contraction of the palatal muscles. Differentiation between essential PT (EPT) and symptomatic PT (SPT) is based on
the clinical and radiological findings.3 The palatal movements consist of activation of the tensor veli palatini muscle in EPT and of the
levator veli palatini muscle in SPT. The common causes of PT include cerebrovascular disease, multiple sclerosis, tumors, trauma,
Behcet’s disease and encephalitis.3 PT after infarction of the brainstem or cerebellum is due to denervation supersensitivity of the
inferior olive from lesions of the dentato-rubro-olivary pathway.
Lesions due to cerebrovascular diseases are the most common
cause of SPT.3
SPT develops between 2 months and 49 months from the onset
of the initial lesion, with most reporting development at

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Case Reports / Journal of Clinical Neuroscience 20 (2013) 757–759

Fig. 1. (A–C) Axial (A) T2-weighted fluid-attenuated inversion recovery (FLAIR), (B) diffusion weighted image, and (C) apparent diffusion coefficient map showing patchy
areas of diffusion restriction within the white matter and the cortex of the posterior and superior left frontal lobe and the posterior left parietal lobe near the vertex. Axial (D)
T2-weighted FLAIR and (E) T2-weighted MRI showing no enlargement or signal changes in the inferior olive.

10–11 months. The involuntary movement of the soft palate is
evoked only after the development of further changes in neural circuitry involving pseudohypertrophy of the inferior olivary nucleus
as a long-term sequela of the former lesions, possibly resulting
from transsynaptic degeneration. There are two noteworthy characteristics in this patient: (i) the rapid development of PT after
an ischemic brain insult; and (ii) the absence of brainstem, cerebellar, or basal ganglia lesions, and the presence of cortical lesions
only, resulting in PT.
We hypothesize that in our patient, the onset of PT is the result of either epileptiform activity arising from the left frontal
motor cortex or diaschisis, where the cortical infarction temporarily produced dysfunction of its subcortical connections within
the dentato-rubro-olivary pathway. The preceding seizure-like
activity of the arm and face, the associated expressive aphasia,
the effective abolition of PT after administration of lorazepam
and complete remission of symptoms after introduction of levetiracetam, suggest an epileptogenic etiology as the most likely
explanation.
The postulated pathways for the cortex to produce PT are attributed to corticobulbar fibers that may arise from the frontal cortex.4
These fibers descend bilaterally to innervate the reticular nuclei,
which in turn send efferents to the nucleus ambiguous, which supplies motor fibers to the vagus nerve that innervates the palatal

musculature. The plausibility of this pathway was shown by Tatum
et al.,1 who reported a patient with PT of cortical origin diagnosed
on the basis of an electroencephalogram and single-photon emission CT scan. These tests showed an area of increased cerebral perfusion in the centrotemporal region.
Additional evidence to support that cortical pathways are involved in the development of PT arise from Haller et al.5 Blood oxygenation level–dependent functional MRI performed in a patient
with PT was associated with peak neuronal activation in the putamen bilaterally. Further neuronal activation was present bilaterally
in the precentral gyrus, as well as the right superior temporal and
angular gyrus.5
The pharmacotherapy of PT with clonazepam, valproate, sumitriptan and trihexyphenidyl has had variable success. Chemodenervation with botulinum toxin injection to palatal muscles using
electromyographic guidance has been useful in the treatment of
PT. The PT in this patient appeared to respond to lorazepam and
did not recur while on levetiracetam, which is likely a result of
its presumed epileptic nature.
4. Conclusions
This report provides further evidence of the central role of the
cortex in the generation of PT. A cortical origin of SPT should be

Case Reports / Journal of Clinical Neuroscience 20 (2013) 759–760

considered in patients presenting after an acute ischemic
insult, particularly if there is no evidence of a brainstem lesion. Potential causes of SPT of cortical origin include focal epilepsy and
diaschisis.

Appendix A. Supplementary data
Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.jocn.2012.05.049.

759

References
1. Tatum WO, Sperling MR, Jacobstein JG. Epileptic palatal myoclonus. Neurology
1991;41:1305–6.
2. Noachtar S, Ebner A, Witte OW, et al. Palatal tremor of cortical origin presenting
as epilepsia partialis continua. Epilepsia 1995;36:207–9.
3. Deuschl G, Toro C, Valls-Solé J, et al. Symptomatic and essential palatal tremor 1.
Clinical, physiological and MRI analysis. Brain 1994;117:775–88.
4. Carpenter MB. Core text of neuroanatomy. 3rd ed. Baltimore: Williams & Wilkins;
1985. p. 111.
5. Haller S, Winkler DT, Gobbi C, et al. Prominent activation of the putamen during
essential palatal tremor: a functional MR imaging case study. AJNR Am J
Neuroradiol 2006;27:1272–4.

doi:http://dx.doi.org/10.1016/j.jocn.2012.05.049

Tropical spastic paraparesis treated with Combivir (lamivudine–zidovudine)
Syed Hassan a,⇑, Syed Amer a, Marcus Zervos b
a
b

Department of Medicine, Henry Ford Hospital, 2799 West Boulevard, Detroit 48202, MI, USA
Department of Infectious Disease, Henry Ford Hospital, Detroit, MI, USA

a r t i c l e

i n f o

Article history:
Received 12 May 2012
Accepted 27 May 2012

Keywords:
Combivir
Human T-lymphotropic virus type 1
Tropical spastic paraparesis

a b s t r a c t
Tropical spastic paraparesis (TSP) or human T-cell leukemia virus–type 1 (HTLV–I)-associated myelopathy is caused by human T-lymphotropic virus type 1. It is a slow, progressive spastic paraparesis with significant morbidity and causing profound repercussions on quality of life. No therapies have been found to
persistently improve the outcome in these patients. We present a patient with HTLV–1-associated myelopathy/TSP (HAM/TSP) who was treated with CombivirÒ (lamivudine–zidovudine, GlaxoSmithKline,
London, UK). She was walker-dependent for several years but, soon after treatment with lamivudine–
zidovudine, was able to walk using only a cane. The role of lamivudine–zidovudine should be investigated further in this patient population.
Published by Elsevier Ltd.

1. Case report
We present a 72-year-old woman with a past medical history of
hypothyroidism, hyperparathyroidism, depression and anxiety who
was diagnosed 15 years ago with human T-cell leukemia virus–type
1 (HTLV–1) associated myelopathy/TSP (HAM/TSP) with a positive
serum antibody to HTLV-1 (the diagnostic study for HAM/TSP at that
time). Her presentation started with increasing falls and a peculiar
sensation in her legs. This evolved into an unsteady, clumsy gait with
spasticity, neuropathic pain, paraparesis and bladder and bowel
incontinence. A brain MRI revealed abnormal fluid attenuated inversion recovery (FLAIR) signal in the subcortical, deep, and periventricular white matter of both frontal lobes and patchy FLAIR
abnormality of the pons suggestive of an inflammatory process
(Fig. 1). She was not offered treatment at the time as there was no
treatment available. Her condition continued to deteriorate and
she eventually became walker-dependent. This disability resulted
in a major depression episode. She scored a 7.0 on the Expanded Disability Status Scale (EDSS), which is a scale used to measure mobility
and is typically used for patients with multiple sclerosis. Her frustration began to grow and she became desperate for any treatment option. Fifteen years after diagnosis, and after much consideration and
discussion with her, she was started on CombivirÒ (lamivudine–
zidovudine; GlaxoSmithKline, London, UK) 150/300 mg tablet twice
per day. Initially, she experienced some abdominal discomfort;
however, within 1 month after the initiation of treatment, she noticed that the spasticity in her legs had decreased although her lower
⇑ Corresponding author. Tel.: +1 773 681 6720; fax: +1 313 916 9100.
E-mail address: shassan2@hfhs.org (S. Hassan).

extremity weakness was unchanged. After 3 months of continued
treatment, her spasticity had significantly decreased; she was able
to ambulate using a cane. Her lower extremity weakness had much
improved. She stopped falling after 5 months of treatment. After
7 months of follow-up after starting lamivudine–zidovudine, her
EDSS score improved to 3.0. To the date of writing, she has been
on treatment for 9 months and continues to improve. Thus, lamivudine–zidovudine appeared to provide symptomatic relief in this patient who suffers from HAM/TSP and greatly improved her quality of
life.
2. Discussion
HTLV-1 is the etiological agent of HAM/TSP. It affects affects
fewer than 2% of carriers of HTLV-1.1 Women are affected more frequently than men due to the higher prevalence of HTLV-1 infection
in women. Disease onset occurs at an average age of 40 years. It is a
chronic meningomyelitis of the spinal cord grey and white matter
with perivascular demyelination and axonal degeneration caused
by HTLV-1. Patients typically develop a slow progressive spastic
paraparesis with significant impairment of gait together with
hyperreflexia, ankle clonus and extensor plantar responses, autonomic dysfunction of the bladder/bowel, back pain and sensory
changes.2–4 All these symptoms have profound repercussion on
quality of life. The disease is progressive and without remission.
Diagnosis is made in the setting of chronic spastic paraparesis with
elevated HTLV proviral load. The individual’s immune response
and proviral load correlates with prognosis. There is no curative
treatment, although corticosteroids,4 IFN-b1a5 and danazol6 have
shown limited benefit. One randomized study evaluated the use