molecule, compared to 3 for N-AA at 2.02 ppm. If one
assumes an N-AA concentration of 7 mM, a peak 3.75 times
that of N-AA could arise from a FFAlDAG concentration
of no more than 1 to 2 mM/kg. The Siesjo study (referenced
by Dr Detre) found a peak FFA concentration of 0.44 mM/
kg but did not measure DAG. We have not claimed that the
lipid signal we observe definitely arises from phosphatidylinositol breakdown products, but simply suggested that it is one
reasonable mechanism to account for the result; the numbers
above seem to us consistent with that suggestion.
We would summarize as follows: Not only do the ‘H MRS
resonances of lactate and lipid overlap, but the potential
causes of increases in brain concentrations of the two metabolites may also overlap. A recent report 141 demonstrated that
it is not sufficient to report lactate increase at long TE [ 5 ]
without having looked for possible simultaneous lipid increases at short TEs.

Nezrology Department
Harvard Medical School
Baton, M A
M c k a n Hospital
Belmont, M A

References
1. Woods BT, Chiu T-M. In vivo ‘H spectroscopy of the human
brain following electroconvulsive therapy. Ann Neurol 1990;
28:745-749
2. Bruhn H, Frahm J, Glyngell ML, et al. Cerebral metabolism in
man after acute stroke: new observations using localized proton
NMR spectroscopy. Magn Reson Med 1989;9:126-131
3. Derome AE. Modern NMR techniques for chemistry research.
New York: Pergamon Press, 1987:114-116
4. Sotak CH, Alger JR. A pitfall associated with lactate detection
using stimulated-echo proton spectroscopy. Magn Reson Med
1771;17:533-538
5. Detre JA, Wang 2, Bogdan AR, et al. Regional variation in brain
lactate in Leigh syndrome by localized ‘H magnetic resonance
spectroscopy. Ann Neurol 1991;29:218-221

The Dysarthria-Clumsy
Hand Syndrome: Ataxic or
Bradykmetic Hand?
F. Grandas, MD, J. A. Villanueva, MD, D. Mateo, MD,
and S. Gimenez-Roldin, M D
The term dysarthria-clumsy hand syndrome (DCHS) was
coined by Fisher [l] to identify a lacunar stroke characterized
chiefly by the combination of dysarthria and “clumsiness” of
one hand. It is commonly related to small infarcts in the basis
pontis [2, 31, but other anatomical localizations have been
sumested [4}.“Clumsiness,” however, is a vague term whose
actual nature has not been precisely defined. It was initially
described as “awkwardness, slowness of fine manipulations,
difficulty in writing, wavering ataxia on the finger-nose test
not clearly cerebellar in type. . .” [I] and no further clarification was made in a more recent review of the topic [ S ] .

CT scan perfrmed 2 days after the onset of symptoms showing
a small, well-defined area of hypodensity in the subcortical
white matter underneath the lt$t SMA.
Glass and associates [ 2 ) reported a consistent clinicalanatomical correlation in patients with the DCHS. In their
series “clumsiness” was regarded as a cerebellar type ataxia.
All patients were found to have small infarcts in the contralatera1 basis pontis by magnetic resonance imaging. These authors suggested a disruption of cerebellar pathways as the
main pathophysiological mechanism of the DCHS.
We describe a patient with the DCHS whose clumsiness
was the consequence of focal bradykinesia caused by a lacunar infarct underlying the left supplementary motor area
(SMA). A 62-year-old diabetic man was admitted to the Hospital General Gregorio Maraii6n in October 1787 because
of transient diplopia. At that time the neurological examination and a brain computed tomography (CT) scan were normal. H e was readmitted in June 1790 complaining of slurred
speech and clumsiness of the right hand of sudden onset. On
examination his mental status was normal and there was no
buccofacial apraxia nor facial weakness. Speech was slow and
dysarthric without dysphasic elements. There was slight pronation of the outstretched right arm, but power was normal
in both proximal and hand muscles. Tendon reflexes were
symmetrical but a transient right Babinski sign was found.
There was no sensory loss. H e performed extremely slowly
simple repetitive, sequential, and alternate movements with
the right hand. The patient could manipulate objects with
this hand but in a slow and inefficient manner, and writing

430 Annals of Neurology Vol 30 No 3 September 1771

was micrographic. There was no ataxia in the finger-to-nose
and heel-to-knee tests. Gait was normal, although a reduced
right arm swing was observed. There was no tremor and
muscle tone was normal. Formal tests for apraxia did not
show significant abnormalities. A brain CT scan showed an
area of hypodensity in the subcortical white matter in the
left hemisphere underlying the SMA (Fig). The patient was
discharged 3 weeks later with a right hand motor function
nearly normal.
This case illustrates a variant of DCHS, different in its
anatomical and pathophysiological basis from that of Glass
and associates 12). Our patient’s clumsiness was in fact bradykinesia, probably related to the lesion underneath the SMA,
which may produce deafferentation of this area of the frontal
cortex from the basal ganglia [6]. Indeed, patients with SMA
lesions may experience difficulty in performing simple but
mainly simultaneous and sequential movements, showing a
motor disorder similar to that of patients with Parkinson’s
disease 16, 71.
We believe that the DCHS should be more precisely
defined. Terms such as “dysarthria-ataxic hand” or “dysarthria-bradykinetic hand” might be useful to improve
clinical-anatomical correlations.

ness and “clumsiness” which appeared as ataxic movements.
The patient described by Grandas and associates did not have
facial weakness and his motor abnormality is characterized as
“bradykinetic,” without ataxia. Therefore, we would not have
labeled this patient as having the dysarthria-clumsy hand
syndrome. Also, this patient’s lesion was defined solely by
computed tomography. Although we would not have predicted a lesion in the basis pontis, the lack of magnetic resonance images (MRIs) makes it difficult to exclude other lesions.
We agree that the clinical syndromes in question need to
be more precisely defined, as we have done for the dysarthria-clumsy hand syndrome. The introduction of MFU
technology into everyday practice allows us to localize precisely small lesions in the brain. If we are to use this technology to further our understanding of how the brain works, it
behooves us to categorize and quantitate neurological dysfunction better, so that the “clinical” can approach the accuracy of the “anatomical”in the clinical-anatomical correlation.

Semicio de Neurologia
Hospital General “Gregorio M a r a n W
Madrid, Spain

RefereenceJ

References
1. Fisher CM. A lacunar stroke. The dysarthria-clumsy hand syndrome. Neurology 1967;17:614-6 17
2. Glass JD, Levey AI, Rothstein JD. The dysarthria-clumsy hand
syndrome: a distinct clinical entity related to pontine infarction.
Ann Neurol 1990;27:487-494
3. Arboix A, Marti-VilaltaJL, Garcia JH. Clinical study of 227 patients with lacunar infarcts. Stroke 1990;21:842-847
4. Orgogozo JM, BogousslavskyJ. Lacunar syndromes. In: Vinken
PJ, Bruyn GW, Klawans HL, eds. Vascular diseases part 11. Handbook of clinical neurology. Amsterdam: Elsevier, 1989;54:
235-27 1
5. Fisher CM. Iacunar strokes and infarcts: a review. Neurology
1982;32:87 1-876
6. Dick JP, Benecke R, Rothwell JC, et al. Simple and complex
movements in a patient with infarction of the right supplementary
motor area. Movement Dis 1986;1:255-266
7. Benecke R, Rothwell JC, Dick JP, et al. Performance of simultaneous movements in patients with Parkinson’s disease. Brain
1986;109:739-757

Reply

Jonathan D. Glass, MD, Allan I. Levey, MD, PhD,
and Jeffrey D. Rothstein, MD, PhD
We appreciate the comments of Grandas and associates [ 11
regarding the localization of lesions responsible for the
dysarthria-clumsy hand syndrome. We believe that the case
outlined in their letter illustrates a major point of our paper
[ 2 ) , that a distinctive clinical picture, based on the precise
definition of findings, predicts a lesion in the basis pontis.
Specifically, our methods section describes the inclusion criteria used for identifying patients with the dysarthria-clumsy
hand syndrome. All of our patients had “central” facial weak-

Neuropathology Luboratoq,
TheJohns Hopkins University School of Medicine
Baltimore. M D

1. Grandas F, Villanueva JA, Mateo D. Gimenez-Roldan S. The
dysarrhria-clumsy hand syndrome: ataxic or bradykinetic hand?
Ann Neurol 1991;30:430-431
2. Glass JD, k v e y AI, Rothstein JD. The dysarthria-clumsy hand
syndrome: a unique clinical entity related to pontine infarction.
Ann Neurol 1990;27:487-494

Does a Retrovirus Cause
Amyotrophic Lateral
Sclerosis?
W. King Engel, MD

In their review of earlier amyotrophic lateral sclerosis (ALS)
patients having lymphoma, Younger and associates [1) cited
our 1964 article [ 2 } describing a patient with lymphosarcoma
(malignant lymphoma). We point our that autopsy confirmation of his degeneration in the corticospinal tracts and lower
motor neurons was subsequently illustrated 131. Younger and
colleagues raised the question of a retrovirus causing both
disorders in their 9 patients plus 23 from the literature. Another of our early patients [2, 31 had chronic lymphocytic
leukemia, which also can be caused by a retrovirus.
From a different approach, I have also recently raised the
question of a retrovirus causing ALS. Based on a comparison
of ALS with human T-lymphotropic virus type I (HTLV-1)associated myelopathy (HAM) (Table) 141, my suggestion
was that there may be a putative “human ALS virus (HAV),”
which in different patients can act (1) directly on neurons,
(2) indirectly through a metabolic mechanism involving intermediate Cells-X, or (3) indirectly through a dysimmune
mechanism.

Annals of Neurology

Vol 30 No 3 September 1991 431