Factors limiting maximal oxygen uptake in exertional monoparesis

Strength and maximal oxygen uptake (VO2max) for each leg were compared in a trained multiple sclerosis (MS) patient with exertional left monoparesis. Left quadriceps strength and left leg VO2max were 22% and 30% lower, respectively, compared to the right (control) leg. Because the same O2 delivery system served each leg during exercise, VO2max of the paretic leg was not limited by cardiorespiratory factors but rather by strength and/or muscle oxidative capacity. However, training with monoparesis likely enhanced O2 extraction and aerobic work capacity of the right leg.

Widespread sequence variations in VAMP1 across vertebrates suggest a potential selective pressure from botulinum neurotoxins

Botulinum neurotoxins (BoNT/A-G), the most potent toxins known, act by cleaving three SNARE proteins required for synaptic vesicle exocytosis. Previous studies on BoNTs have generally utilized the major SNARE homologues expressed in brain (VAMP2, syntaxin 1, and SNAP-25). However, BoNTs target peripheral motor neurons and cause death by paralyzing respiratory muscles such as the diaphragm. Here we report that VAMP1, but not VAMP2, is the SNARE homologue predominantly expressed in adult rodent diaphragm motor nerve terminals and in differentiated human motor neurons. In contrast to the highly conserved VAMP2, BoNT-resistant variations in VAMP1 are widespread across vertebrates. In particular, we identified a polymorphism at position 48 of VAMP1 in rats, which renders VAMP1 either resistant (I48) or sensitive (M48) to BoNT/D. Taking advantage of this finding, we showed that rat diaphragms with I48 in VAMP1 are insensitive to BoNT/D compared to rat diaphragms with M48 in VAMP1. This unique intra-species comparison establishes VAMP1 as a physiological toxin target in diaphragm motor nerve terminals, and demonstrates that the resistance of VAMP1 to BoNTs can underlie the insensitivity of a species to members of BoNTs. Consistently, human VAMP1 contains I48, which may explain why humans are insensitive to BoNT/D. Finally, we report that residue 48 of VAMP1 varies frequently between M and I across seventeen closely related primate species, suggesting a potential selective pressure from members of BoNTs for resistance in vertebrates.

Botulinum neurotoxins (BoNTs) target peripheral motor neurons and act by cleaving SNARE proteins, which are essential for neurotransmitter release from nerve terminals. SNARE proteins occur in multiple homologues and it has been difficult to determine which one is the physiologically relevant toxin target in motor nerve terminals among closely related SNARE homologues such as VAMP1 and VAMP2. Here we report that, in contrast to the highly conserved VAMP2, sequence variations in VAMP1 that confer resistance to BoNTs are widespread across vertebrates. In particular, residue 48 of VAMP1 is polymorphic between BoNT/D-sensitive residue M and BoNT/D-resistant residue I in rats. Taking advantage of this finding, we carried out an intra-species comparison, which showed that diaphragm motor nerve terminals from rats with I48 in VAMP1 were insensitive to BoNT/D as compared to those with M48. Since VAMP2 is conserved in rats, these data demonstrate that VAMP1 is the physiologically relevant toxin target in motor neurons. Interestingly, human VAMP1 encodes the BoNT/D-resistant residue I48, which may explain why humans are insensitive to BoNT/D. Finally, we found that residue 48 of VAMP1 switches frequently between M and I among 17 primate species, suggesting a potential selective pressure from BoNT/D for resistance in primates.

D-dimer elevation and paresis predict thromboembolic events during bevacizumab therapy for recurrent malignant glioma

BACKGROUND

The major side-effects of bevacizumab in glioma treatment are venous thromboembolic events (VTE). We retrospectively evaluated factors potentially predictive of thromboembolic events.

PATIENTS AND METHODS

Bevacizumab, alone or in combination with chemotherapy was used as salvage therapy for recurrence in malignant glioma every two weeks. None but one patient received anti-coagulants. Before each bevacizumab cycle differential blood cell count, kidney and liver parameters, D-dimers, neurological status, body-mass index, vital signs and signs of venous thrombosis were assessed.

RESULTS

Thirty-eight patients received 428 cycles of bevacizumab. In five patients (13%), six VTE were observed. These complications were preceded four weeks before the onset of symptoms by D-dimer elevation above 0.865 mg/l [p<0.0001; sensitivity=89% (95% confidence interval=83-93%); specificity=89% (95% CI=52-100%)]. An existing hemiparesis constituted a 27-fold risk elevation for thrombotic complication (p<0.0001, χ(2)-test).

CONCLUSION

D-Dimer elevation or hemiparesis predict VTE under bevacizumab and chemotherapy, four weeks before the event becomes clinically apparent. Future investigations should determine if prophylactic anti-coagulants for patients at risk may reduce the risk of VTE.

Biological and biochemical characterization of mice expressing prion protein devoid of the octapeptide repeat region after infection with prions

Accumulating lines of evidence indicate that the N-terminal domain of prion protein (PrP) is involved in prion susceptibility in mice. In this study, to investigate the role of the octapeptide repeat (OR) region alone in the N-terminal domain for the susceptibility and pathogenesis of prion disease, we intracerebrally inoculated RML scrapie prions into tg(PrPΔOR)/Prnp(0/0) mice, which express mouse PrP missing only the OR region on the PrP-null background. Incubation times of these mice were not extended. Protease-resistant PrPΔOR, or PrP(Sc)ΔOR, was easily detectable but lower in the brains of these mice, compared to that in control wild-type mice. Consistently, prion titers were slightly lower and astrogliosis was milder in their brains. However, in their spinal cords, PrP(Sc)ΔOR and prion titers were abundant and astrogliosis was as strong as in control wild-type mice. These results indicate that the role of the OR region in prion susceptibility and pathogenesis of the disease is limited. We also found that the PrP(Sc)ΔOR, including the pre-OR residues 23-50, was unusually protease-resistant, indicating that deletion of the OR region could cause structural changes to the pre-OR region upon prion infection, leading to formation of a protease-resistant structure for the pre-OR region.

Distribution of inducible nitric oxide synthase and tumor necrosis factor-alpha in the peripheral nervous system of Lewis rats during ascending paresis and spontaneous recovery from experimental autoimmune neuritis

BACKGROUND

Inducible nitric oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-alpha) are pleiotropic molecules with widespread action in autoimmune diseases.

OBJECTIVE

This study characterizes the distribution of iNOS and TNF-alpha in the spinal nerve roots, dorsal root ganglia and sciatic nerve of Lewis rats during experimental autoimmune neuritis (EAN).

METHODS

Macrophages and neutrophils were identified by immunofluorescence as cellular sources of iNOS and TNF-alpha at various stages of EAN induced by synthetic peptide 26.

RESULTS

As the disease progressed, iNOS- and TNF-alpha-bearing cells gradually infiltrated the cauda equina, dorsal root ganglia, Th12-L3 spinal roots, and the sciatic nerve. A severer EAN profile developed when more iNOS- and TNF-alpha-bearing cells were present, and the recovery from EAN was related to the disappearance of these cells and the regeneration of nerve fibers.

CONCLUSIONS

This is the first report to show iNOS- and TNF-alpha-immunoreactive cells in dorsal root ganglia during EAN, suggesting an underlying pathology for the neuropathic pain behavior in EAN. Our results suggest that the cells bearing iNOS and TNF-alpha in the different parts of the peripheral nervous system are involved in the development of the clinical signs observed at each stage of EAN.

A proteomics analysis of the effects of chronic hemiparetic stroke on troponin T expression in human vastus lateralis

Stroke disability is attributed to upper motor neuron deficits resulting from ischemic brain injury. We have developed proteome maps of the Vastus lateralis to examine the effects of ischemic brain injury on paretic skeletal muscle myofilament proteins. Proteomics analyses from seven hemiparetic stroke patients have detected a decrease of three troponin T isoforms in the paretic muscle suggesting that myosin-actin interactions may be attenuated. We propose that ischemic brain injury may prevent troponin T participation in complex formation thereby affecting the protein interactions associated with excitation-contraction coupling. We have also detected a novel skeletal troponin T isoform that has a C-terminal variation. Our data suggest that the decreased slow troponin T isoform pools in the paretic limb may contribute to the gait deficit after stroke. The complexity of the neurological deficit on Vastus lateralis is suggested by the multiple changes in proteins detected by our proteomics mapping.

The influence of different Lokomat walking conditions on the energy expenditure of hemiparetic patients and healthy subjects

To determine the strenuousness and efficacy of therapy, the energy expenditure of 10 healthy and 10 hemiparetic subjects were measured while they walked on a treadmill that was combined with a robot-driven gait orthosis, the Lokomat, which physiologically exercises the legs of a patient on a moving treadmill. Subjects performed different Lokomat conditions after measurement of the baseline, i.e., standing in the Lokomat with 30% body weight support (BWS). Robotic strategies with a position control scheme used fixed gait patterns to produce the following conditions: walking with 100% BWS at a speed of 1 km/h versus 2 km/h and walking with 30% BWS at a speed of 1 km/h versus 2 km/h. Another robotic control option with a force control scheme allowed the force to be reduced on only one leg of the orthosis. In this option a reduction to 60% and to 0% assistance was tested. Oxygen consumption and heart rate were measured by a breath-by-breath respiratory gas analyzing system using standard open circuit methodology. The results for O(2) rate [ml/kg/min] indicate that: (1) walking in the Lokomat is not passive; (2) oxygen uptake is significantly increased due to an effect of loading during active stance phase; (3) speed is not a factor leading to increased oxygen consumption; (4) patients do not significantly increase their oxygen uptake due to the advanced force control scheme.

Neuroimaging and histopathological evaluation of delayed neurological damage produced by artificial occlusion of the middle cerebral artery in Cynomolgus monkeys

A monkey model (Cynomolgus) was established to evaluate the delayed neurological damage evident at areas distant from ischemic cerebral foci. In addition to proton magnetic resonance spectroscopy (MRS) monitoring in life, histological examinations of specimens of the brain was conducted on lesions produced 6h and 1, 2, 4 and 8 weeks after unilateral (left) permanent middle cerebral artery occlusion (pMCO) on five monkeys. In addition to the typical images evident at primary ischemic foci around the middle cerebral artery, MRS revealed and enhanced, clearer region, due to edema extending into the reticular and compact area of the left substantia nigra one week after pMCO, inducing right hemiparesis caused by focal cerebral ischemia. Similar histological lesions were also induced in the left thalamus 4 weeks after pMCO. Thereafter, a variety of histological findings including astrocytic activation, reduced number of nerve cells and gliosis were found in the above described areas far apart from the original ischemic cerebral foci. Our monkey model should be suitable for studies elucidating the pathological process in cerebral ischemia as well as for investigating therapeutic strategies involving ischemic stroke in humans.

Changes in fiber integrity, diffusivity, and metabolism of the pyramidal tract adjacent to gliomas: a quantitative diffusion tensor fiber tracking and MR spectroscopic imaging study

BACKGROUND AND PURPOSE

The underlying changes in the neuronal connectivity adjacent to brain tumors cannot always be depicted by conventional MR imaging. The hypothesis of this study was that preoperative sensorimotor deficits are associated with impairment in pyramidal fiber bundles. Hence, we investigated the potential of combined quantitative diffusion tensor (DT) fiber tracking and MR spectroscopic imaging (MRSI) to determine changes in the pyramidal tract adjacent to gliomas.

MATERIALS AND METHODS

Quantitative DT fiber tracking and proton MRSI were performed in 20 patients with gliomas with WHO grades II-IV. Eight patients experienced preoperative sensorimotor deficits. Mean diffusivity (MD), fractional anisotropy (FA), and number of fibers per voxel (FpV) were calculated for the pyramidal tract of the ipsilateral and contralateral hemisphere. Metabolite concentrations for choline-containing compounds (Cho), creatine (Cr), and N-acetylaspartate (NAA) were computed, using LCModel, for all voxels located at the pyramidal tracts.

RESULTS

For the whole pyramidal tract, quantitative DT fiber tracking resulted in significantly lower FpV and FA values (P < .001), but not MD values, for the ipsilateral hemisphere. For the section of the fiber bundle closest to the lesion, we found significantly decreased FpV and FA (P < .001) and increased MD (P = .002). MRSI showed, for the same volumes of interest, significantly decreased NAA (P = .001), increased Cho (P = .034) and Cho/NAA (P = .001) for the ipsilateral pyramidal tract. In patients suffering sensorimotor deficits, we found significantly lower FA (P = .022) and higher MD values (P = .026) and a strongly negative correlation between FA and MD (R = -0.710, P = .024) but no correlation in patients without deficits (R = 0.078, ns).

CONCLUSION

Quantitative DTI was able to show significant differences in diffusivity of the pyramidal tract in patients with sensorimotor deficits in relation to patients without them. The additional use of proton MRSI may be helpful to discern whether these diffusivity changes in fiber tracts are caused by tumor infiltration or peritumoral edema.

Decreased capillarization and a shift to fast myosin heavy chain IIx in the biceps brachii muscle from young adults with spastic paresis

Muscle spasticity and paresis are conditions that occur secondary to upper motor neuron lesions. The co-existence of decreased motor unit recruitment and intermittent over-activity generates confusion concerning the effect on muscle fiber characteristics. In order to increase the knowledge about the effect of upper motor lesion on capillarization and muscle fiber composition, the biceps brachii muscle from seven young adults with long duration of spastic paresis and seven age-matched controls were analyzed using morphological and enzyme- and immuno-histochemical techniques. The spastic muscles had a 38% lower capillary density (p=0.002), 30% fewer capillaries around each muscle fiber (p=0.02), and 16% fewer capillaries when related to the fiber size (p=0.04). The frequency of fibers expressing myosin heavy chain (MyHC) IIx increased (30% vs. 4%, p=0.006), while the percentage of fibers expressing MyHC I and MyHC IIa, respectively, decreased (22% vs. 46% and 7% vs. 29%, p<0.01). The high proportion of muscle fibers with low oxidative capacity and low capillary supply indicates that biceps brachii muscle from patients with upper motor lesions fatigue more easily than normal controls. We also observed a significantly higher variability in fiber size for fibers expressing MyHC I (p<0.04), and, in three of the subjects, a small amount of small fibers expressing developmental MyHCs was found. These results suggest that, although intermittent stretch reflex contractions might have an impact on the muscle characteristics in spastic paresis, the muscle phenotypic properties are more adapted to decreased voluntary motor unit recruitment.

In vivo brain microdialysis studies on the striatal dopamine and serotonin release in zitter mutant rats

In the present study, using in vivo brain microdialysis, we investigated the basal extracellular dopamine (DA) and serotonin (5-HT) release in the caudal striatum (cSTR) of young (4-6 months old) and aged (10-12 months old) zitter mutant rats. The basal extracellular levels of DA release in both young and aged zitter rats were significantly lower than that of age-matched Sprague-Dawley (SD) rats, whereas only aged zitter rats showed a significant difference in the basal 5-HT release. Dopaminergic neurons were more vulnerable than serotonergic neurons in the cSTR of zitter mutant rats during aging. Perfusion of 60 mM potassium (K+) enhanced the extracellular levels of cSTR DA in the young zitter rats and the extracellular levels of both DA and 5-HT in the cSTR of the aged zitter rats. The firing rate of K+-stimulated monoamine release in the cSTR was significantly higher in the zitter rats than in the age-matched SD rats. These findings suggest that there are innate quantitative differences in the releasable pool and the availability of monoamines in the cSTR of zitter mutant rats.

Physical rehabilitation of stroke patients and redox alterations

We studied 43 acute stroke patients: 22 patients were randomly assigned to the experimental group and 21 patients - to the control group. Experimental group patients underwent neuro-muscular electric stimulation (NMES) in addition to standard rehabilitation regimen. Pro- and antioxidant activity was evaluated at admission and at the end of acute stage: paramagnetic centers of blood (ceruloplasmin, Fe(3+) transferrin, Mn(2+), Fe(2+), MetHb, NO, HbNO, FeSNO) were investigated by EPR-spectroscopy. We observed excessive formation of promoters of free-radical oxidation and inactivation of antioxidative protection system. Concentration of free NO was decreased in majority of the patients. Following NMES application, we observed normalization of almost every parameter of redox system: inactivation of Fe(3+) and Mn(2+) ions, increase of total concentration of ceruloplasmin and decrease of its oxidation degree, increase of Fe(3+) transferrin level, decrease of MetHb concentration, normalization of free NO. These alterations were more prominent compared to the control group patient (p<0,05). We conclude, that NMES facilitates restoration of the balance between pro- and antioxidative systems and decreases intensity of oxidative stress.

Interaction between the levels of hormones and minerals in sera of healthy and sick cows

An interaction between blood levels of parathyroid hormone, calcitonin, 1.25-dihydroxycholecalciferol and levels of calcium, phosphorus and magnesium was examined in 85 cows, which included healthy cows and cows with ostemalacia, mastitis and paresis. Levels of parathyroid hormone (PTH) and calcitonin were determined in vitro using IMMULITE analyser (Diagnostic Products Corporation, USA), by means of immunometric assay. Levels of vitamin D were measured using the enzyme linked immunosorbent assay (ELISA). Levels of calcium, phosphorus and magnesium were determined using the automated Eos-Bravo analyser (Hospitex Diagnostics, Italy) with HOSPITEX reagents. The lowest blood levels of calcium (1.38 +/- 0.18 mmol/L) and phosphorus (0.65 +/- 0.12 mmol/L) were found in cows with parturient paresis. Decreased blood levels of phosphorus and magnesium were also determined in cows with osteomalacia. For cows with parturient paresis, which received a mineral supplement, the average serum level of calcium was by 20.7% higher than the level found in those which did not receive a supplement, and the level of phosphorus was by 23.6% higher, however, these levels remained low. The blood level of parathyroid hormone ranged from 3.47 to 5.20 pmol/L in healthy cows and from 3.95 to 15.21 pmol/L in sick cows. The highest and statistically significant increase in blood PTH level (up to 18.31 +/- 1.88 pmol/L) was found in cows with parturient paresis. The blood level of PTH correlated inversely with the level of calcium in cows with osteomaliacia (r = -0.89) and in cows with parturient paresis (r = -0.49 and r = -0.61, respectively). The serum level of calcitonin ranged from 1.46 pmol/L to 2.40 pmol/L in healthy and sick cows and the difference was not statistically significant. Lower serum levels of vitamin D were found in heifers-in-calf and in cows with mastitis. A clear correlation between levels of calcitonin, vitamin D and macronutrients was not found.

Rabbit paralytic tremor phenotype--a plp1 gene mutation as a model of human Pelizaeus-Merzbacher disease

The paralytic tremor (pt) disease in rabbits results from a point mutation in a plp gene and manifests itself by a broad range of neurological signs. Biochemical studies have shown that myelinogenesis is retarded and deficient in mutant rabbits. Myelin sheaths are usually thin and malformed. The number of oligodendrocytes is normal, however their differentiation and maturation is prolonged. The effects of the pt mutation were investigated in morphological, biochemical and molecular studies, resulting in the well-documented characteristics of the disease. The pt phenotype and its detailed characteristics make the mutated rabbit a good model of Pelizaeus-Merzbacher disease.

Proton magnetic resonance spectroscopic changes of the primary motor cortex and supplementary motor area in hemiparetic patients with corticospinal tract injury due to deep intracerebral hematoma

This study was conducted to investigate the metabolic changes in the motor and motor association cortices following axonal injury in the internal capsule that was caused by deep intracerebral hematoma. Using proton magnetic resonance spectroscopy (1H MRS), the authors studied the primary motor cortices (M-1) and supplementary motor areas (SMA) of 9 hemiparetic patients with documentable hemiparesis of varying severity, and we studied 10 normal volunteers as controls. To measure the M-1 and SMA biochemical changes, 4 separate single volumes of interest (VOIs) were located bilaterally in the affected and unaffected hemisphere (AH and UH). 1H MRS provided a neuronal and axonal viability index by measuring levels of N-acetylaspartate (NAA) and creatine/phosphocreatine (Cr). The M-1/SMA NAA/Cr ratios of the AH and UH in patients, and the AH and normal volunteers were compared. The NAA/Cr ratios of the M-1 and SMA in AH, and the SMA in UH were significantly lower than those of normal volunteers. These 1H MRS findings indicate that axonal injury in the descending motor pathway at the level of internal capsule could induce metabolic changes in the higher centers of the motor pathway.

[Early nutrition support for intestinal insufficiency syndrome in spine surgery]

Paresis of the gastrointestinal tract resulting in the intestinal insufficiency syndrome (IIS) is a postoperative risk factor in spinal surgery. One hundred and twenty patients with fractures at L1-L2 spine level, isthmic spondylolisthesis, osteochondrosis and with sever neurological symptoms were examined and treated. The intestinal motor-evacuation malfunction, hypermetabolism, microbial translocation and immunity impairments are observed in IIS. Early nutritional support is indicated for the IIS prevention and treatment. Enteral feeding with new balanced mixtures containing fibers is effective.

Hemiparetic muscle atrophy and increased intramuscular fat in stroke patients

OBJECTIVE

To determine if skeletal muscle atrophy and greater fat deposition within the muscle are present in the hemiparetic limb of chronic (>6 mo) hemiparetic stroke patients.

DESIGN

Cross-sectional study.

SETTING

Hospital-based research center.

PARTICIPANTS

Sixty patients (47 men, 13 women; mean age +/- standard deviation, 65+/-9 y).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Patients underwent a total body scan by dual-energy x-ray absorptiometry to determine percentage of body fat, total lean mass, fat mass, and lean mass of the paretic and nonaffected legs, thighs, and arms. Thirty patients received computed tomography (CT) scans of their midthigh to determine muscle area, subcutaneous fat, and low-density lean tissue, as a measure of fat within the muscle area, of the paretic and nonaffected midthigh.

RESULTS

Patients were deconditioned (VO(2)peak: 1.2+/-0.3 L/min) with a percentage of body fat of 31.4%+/-9.8% and total lean mass of 51.4+/-9.1 kg. Lean mass of the paretic leg and thigh were 4% and 3% lower than the nonaffected leg (P<.001), but leg fat was not different. Arm lean mass of the paretic side was 7% lower than the nonaffected side, whereas arm fat was not different. CT studies showed that midthigh muscle area was 20% lower in the paretic limb than in the nonaffected leg (P<.001), midthigh subcutaneous fat was similar, and midthigh low-density lean tissue showed a trend to be 3% higher in the paretic leg (P=.06). The ratio of midthigh low-density lean tissue to muscle area was higher in the paretic leg (P<.001), which indicates a greater intramuscular fat relative to muscle area in the affected limb.

CONCLUSIONS

Our results show hemiparetic skeletal muscle atrophy and more fat within the muscle, factors that may contribute to functional disability and increased cardiovascular disease risk in chronic hemiparetic stroke patients.

Effect of upper extremity posturing on measured resting energy expenditure of nonambulatory tube-fed adult patients with severe neurodevelopmental disabilities

PURPOSE

To ascertain the effect of upper extremity posturing on measured resting energy expenditure (MEE) for patients with severe neurodevelopmental disabilities.

METHODS

Twenty-four nonambulatory adult patients with severe neurodevelopmental disabilities referred for evaluation of enteral tube feeding and who had a steady-state MEE performed were studied. Steady-state indirect calorimetry measurements were done through a canopy system. Patients were stratified according to the topography of their neuromotor impairment and motor function as having either fixed upper extremity contractures (Fixed UE) or with preservation of limited functional and nonfunctional upper extremity movement (Preserved UE).

RESULTS

Despite a similar age, weight, height, and gender distribution between groups, those patients with Fixed UE (n = 13) had a significantly lower MEE than those with Preserved UE (n = 11): 893 +/- 91 versus 1144 +/- 262 kcal/d (p < .01), respectively. The Harris-Benedict equations' predicted energy expenditures were similar to MEE for patients with Preserved UE (1212 +/- 156 versus 1144 +/- 262 kcal/d, respectively, p = N.S.). Patients with Fixed UE had a significantly lower MEE than predicted by the Harris-Benedict equations (893 +/- 91 versus 1128 +/- 123 kcal/d, respectively, p < .01)

CONCLUSIONS

Patients with fixed upper extremity contractures have a significantly lower MEE than those with preserved upper extremity movement. MEE for nonambulatory tube-fed adult patients with severe neurodevelopmental disabilities and fixed upper extremity contractures is significantly lower than predicted by the Harris-Benedict equations.

Slowly progressive anarthria with late anterior opercular syndrome: a variant form of frontal cortical atrophy syndromes

We describe eight patients with slowly progressive speech production deficit combining speech apraxia, dysarthria, dysprosody and orofacial apraxia, and initially no other deficit in other language and non-language neuropsychological domains. Long-term follow-up (6-10 years) in 4 cases showed an evolution to muteness, bilateral suprabulbar paresis with automatic-voluntary dissociation and frontal lobe cognitive slowing without generalised intellectual deterioration. Most disabled patients presented with an anterior opercular syndrome (Foix-Chavany-Marie syndrome), and pyramidal or extrapyramidal signs. CT and MRI findings disclosed asymmetric (left > right) progressive cortical atrophy of the frontal lobes predominating in the posterior inferior frontal region, notably the operculum. SPECT and PET revealed a decreased cerebral blood flow and metabolism, prominent in the left posterior-inferior frontal gyrus and premotor cortex, extending bilaterally in the most advanced cases. Pathological study of two cases showed non-specific neuronal loss, gliosis, and spongiosis of superficial cortical layers, mainly confined to the frontal lobes, with no significant abnormalities in the basal ganglia, thalamus, cerebellum, brain stem (except severe neuronal loss in the substantia nigra in one case), and spinal cord. We propose to call this peculiar syndrome Slowly Progressive Anarthria (SPA), based on its specific clinical presentation, and its metabolic and pathological correlates. SPA represents another clinical expression of focal cortical degeneration syndromes, that may overlap with other similar syndromes, specially primary progressive aphasia and the various frontal lobe dementias.

3H-Spiroperidol binding to striatal membranes of mutant Han-Wistar rats which exhibit spastic paresis

The binding of 3H-spiroperidol to striatal membranes from a strain of mutant Han-Wistar rats was compared with that in normal littermate animals. The specific binding was less in the mutants than the controls. Scatchard analysis revealed that the KD- and Bmax-values for the high affinity binding sites in the mutants are greater than for those in the controls. These findings indicate that the dopamine receptors of the mutants are affected and could explain some of the previous data; it has been suggested that some of the spasticity observed in the mutants may be due to an abnormal functioning of their dopaminergic neurones.