Bilateral femoral neck insufficiency fractures secondary to vitamin D deficiency and concurrent corticosteroid use--a case report

We present a rare case of a 67-year-old Indian female who was found to have bilateral insufficiency of the neck of femur fractures secondary to osteomalacia from vitamin D deficiency, with her symptoms exacerbated by a course of oral steroids prescribed for suspected polymyalgia rheumatica.

INTRODUCTION

Bilateral femoral neck fractures are rare and are known to be associated with a variety of conditions such as parathyroid or renal dysfunction.

METHOD

We present a rare case of a 67-year-old Indian female who was found to have bilateral insufficiency of the neck of femur fractures secondary to osteomalacia from vitamin D deficiency, with her symptoms exacerbated by a course of oral steroids prescribed for suspected polymyalgia rheumatica.

RESULT

In patients with severe bilateral hip pain and a normal pelvic radiograph, it is important to consider magnetic resonance imaging early to avoid missing this important diagnosis.

CONCLUSION

Osteomalacia and vitamin D deficiency is an important differential diagnosis in any patient presenting with bone and muscle pain. Vitamin D levels are easily available and deficiency is easily treated.

A comprehensive analysis of deletions, multiplications, and copy number variations in PARK2

OBJECTIVES

To perform a comprehensive population genetic study of PARK2. PARK2 mutations are associated with juvenile parkinsonism, Alzheimer disease, cancer, leprosy, and diabetes mellitus, yet ironically, there has been no comprehensive study of PARK2 in control subjects; and to resolve controversial association of PARK2 heterozygous mutations with Parkinson disease (PD) in a well-powered study.

METHODS

We studied 1,686 control subjects (mean age 66.1 ± 13.1 years) and 2,091 patients with PD (mean onset age 58.3 ± 12.1 years). We tested for PARK2 deletions/multiplications/copy number variations (CNV) using semiquantitative PCR and multiplex ligation-dependent probe amplification, and validated the mutations by real-time quantitative PCR. Subjects were tested for point mutations previously. Association with PD was tested as PARK2 main effect, and in combination with known PD risk factors: SNCA, MAPT, APOE, smoking, and coffee intake.

RESULTS

A total of 0.95% of control subjects and 0.86% of patients carried a heterozygous CNV mutation. CNV mutations found in 16 control subjects were all in exons 1-4, sparing exons that encode functionally critical protein domains. Thirteen patients had 2 CNV mutations, 5 had 1 CNV and 1 point mutation, and 18 had 1 CNV mutation. Mutations found in patients spanned exons 2-9. In whites, having 1 CNV was not associated with increased risk (odds ratio 1.05, p = 0.89) or earlier onset of PD (64.7 ± 8.6 heterozygous vs 58.5 ± 11.8 normal).

CONCLUSIONS

This comprehensive population genetic study in control subjects fills the void for a PARK2 reference dataset. There is no compelling evidence for association of heterozygous PARK2 mutations, by themselves or in combination with known risk factors, with PD.

The ethics surrounding HIV, kidney donation and patient confidentiality

For live-related kidney donation, the current UK guidance specifies that the donor has a right to know the recipient's HIV status. This guidance may prevent some potential recipients from asking friends or family to donate, as they do not wish them to know they are HIV positive. Currently, it is felt necessary that the donor should know the HIV status of the recipient in order to give fully informed consent to the operation. However, the specific medical details are not required in order to allow for donor informed consent. This consent requires knowledge of the general expectation for survival of a graft and the specific expectation for survival of this graft in the recipient; it does not require specific knowledge of the recipient's medical condition.

Axial hypertonicity in Parkinson's disease: direct measurements of trunk and hip torque

A cardinal feature of Parkinson's disease (PD) is muscle hypertonicity, i.e. rigidity. Little is known about the axial tone in PD or the relation of hypertonia to functional impairment. We quantified axial rigidity to assess its relation to motor symptoms as measured by UPDRS and determine whether rigidity is affected by levodopa treatment. Axial rigidity was measured in 12 PD and 14 age-matched controls by directly measuring torsional resistance of the longitudinal axis to twisting (+/-10 degrees ). Feet were rotated relative to fixed hips (Hip Tone) or feet and hips were rotated relative to fixed shoulders (Trunk Tone). To assess tonic activity only, low constant velocity rotation (1 degrees /s) and low acceleration (<12 degrees /s(2)) were used to avoid eliciting phasic sensorimotor responses. Subjects stood during testing without changing body orientation relative to gravity. Body parts fixed against rotation could translate laterally within the boundaries of normal postural sway, but could not rotate. PD OFF-medication had higher axial rigidity (p<0.05) in hips (5.07 N m) and trunk (5.30 N m) than controls (3.51 N m and 4.46 N m, respectively), which did not change with levodopa (p>0.10). Hip-to-trunk torque ratio was greater in PD than controls (p<0.05) and unchanged by levodopa (p=0.28). UPDRS scores were significantly correlated with hip rigidity for PD OFF-medication (r values=0.73, p<0.05). Torsional resistance to clockwise versus counter-clockwise axial rotation was more asymmetrical in PD than controls (p<0.05), however, there was no correspondence between direction of axial asymmetry and side of disease onset. In conclusion, these findings concerning hypertonicity may underlie functional impairments of posture and locomotion in PD. The absence of a levodopa effect on axial tone suggests that axial and appendicular tones are controlled by separate neural circuits.

Parkinson's disease, CYP2D6 polymorphism, and age

OBJECTIVE

PD may be caused by genetic susceptibility to neurotoxins. CYP2D6 is a candidate gene for PD because it regulates drug and toxin metabolism, but association studies have been inconsistent. The aim of this study was to test if the CYP2D6*4 allele (poor metabolizer phenotype) is associated with earlier age at onset.

METHODS

Five hundred seventy-six patients with PD and 247 subjects without PD were studied using standard diagnostic, genotyping, and statistical techniques.

RESULTS

Surprisingly, mean onset age was significantly later in *4-positive patients. Frequency of *4 was significantly higher in late-onset PD than early-onset PD. When early- and late-onset PD were analyzed separately, *4 had no effect on onset age; hence, the association with delayed onset was likely an artifact of an elevated *4 frequency in late-onset PD. Contrary to a common assumption that CYP2D6 frequencies do not change with age, *4 frequency rose significantly with advancing age, both in patients with PD (from 0.16 at mean age of 56.5 years to 0.21 at mean age of 72) and subjects without PD (from 0.09 at mean age of 45.5 years to 0.21 at mean age of 72). *4 Frequencies in patients with early- and late-onset PD, although different from each other, were in agreement with similarly aged subjects without PD, suggesting the elevated *4 frequency in late-onset PD was likely an age effect, unrelated to PD.

CONCLUSION

The CYP2D6*4 allele is not associated with earlier PD onset. *4 May be associated with survival. Inconsistent results from allelic association studies may have been due to an unrecognized age effect.

Exacerbated physical fatigue and mental fatigue in Parkinson's disease

OBJECTIVE

To characterize fatigue in Parkinson's disease (PD).

BACKGROUND

Fatigue is a recognized problem in PD. Fatigue can be in the physical realm or in the mental realm. Fatigue has not been characterized in PD.

METHODS

We characterized fatigue in 39 PD patients and 32 age-matched normal controls using five questionnaires: A. The Multidimensional Fatigue Inventory (MFI), which measures five dimensions of fatigue independently including general fatigue, physical fatigue, reduced motivation, reduced activity, and mental fatigue. B. The Fatigue Severity Inventory (FSI), which quantifies fatigue in general. C. The Profile of Mood States (POMS), which assesses six subjective subscales: tension-anxiety, depression-dejection, anger-hostility, fatigue-inertia, vigor-activity, and confusion-bewilderment. D. Center for Epidemiological Studies-Depression Scale (CES-D). E. Visual Analog linear scale of energy (VA-E).

RESULTS

PD patients scored higher in all of the five dimensions of fatigue in the MFI including general fatigue, physical fatigue, reduced motivation, reduced activity, and mental fatigue (P < 0.001 except for mental fatigue P = 0.005). The severity of physical fatigue did not correlate with that of mental fatigue. PD patients scored higher on the FSI, POMS, CES-D, and scored lower on the VA-E. The scores in the FSI correlated with general fatigue, physical fatigue, reduced activity, and reduced motivation but not with mental fatigue in the MFI. Depression correlated with all dimensions of fatigue except physical fatigue in the MFI. Disease severity, as measured by Modified Hoehn and Yahr staging, did not correlate with any of the measures.

CONCLUSIONS

PD patients have increased physical fatigue and mental fatigue compared to normals. Physical fatigue and mental fatigue are independent symptoms in PD that need to be assessed and treated separately.

Centrally initiated postural adjustments in parkinsonian patients on and off levodopa

This study investigates the effects of parkinsonism and dopamine replacement therapy (levodopa) on centrally initiated postural activity preceding rising onto the toes. The electromyographic (EMG) and force magnitude, scaling, sequencing, and postural stabilization were compared when rising-to-toes under two conditions, slow/low versus fast/high, for parkinsonian patients and elderly control subjects. Parkinsonian subjects were tested after withholding their levodopa medication for 12-16 h and again 1 h after taking their medication when parkinsonian signs were diminished. Parkinsonian subjects showed reduced magnitudes and delayed timing of the postural and voluntary components of the rise-to-toes task, as if they had difficulty turning off the postural, tibialis anterior (TIB) component and initiating the voluntary, gastrocnemius (GAS) component. Dopamine improved the relative timing, as well as the magnitude of both postural and voluntary components of rise-to-toes. Although the magnitude of dorsiflexion torque was smaller for parkinsonian subjects ON and OFF than for healthy elderly controls, the parkinsonian subjects showed intact scaling of the magnitude of postural activity. Parkinsonian subjects do not perform the rise-to-toes task like normal subjects who are instructed to rise slowly; the relative timing of TIB and GAS activation was different even at comparable speeds of performance. Parkinsonian subjects, both ON and OFF, exhibited greater risk of falling than elderly control subjects when rising to toes. This increased risk of falling was reflected in a smaller safety margin between the peak center of mass (CoM) and peak center of pressure (CoP) during the task. The magnitude of mean postural dorsiflexion torque in the rise-to-toes task was highly correlated with a clinical rating scale of gait and balance, suggesting that force control is a critical factor influencing postural control in patients with Parkinson's disease.

Exclusion of dominant mutations within the FTDP-17 locus on chromosome 17 for Parkinson's disease

Parkinson's disease (PD) is a prevalent movement disorder, and 10-30% of PD is familial. Several neurodegenerative disorders which are collectively called frontotemporal dementia and parkinsonism have been mapped to chromosome 17q and mutations in tau have been identified. The clinical and pathological overlap suggests that these related conditions may be due to mutations in tau. We examined linkage to the candidate region on chromosome 17 including and surrounding tau in eight familial PD kindreds. We found no evidence for linkage and excluded the 6cM candidate region which suggest that in our families, PD is not caused by dominant mutations within tau.

A novel nonsense mutation in CACNA1A causes episodic ataxia and hemiplegia

OBJECTIVE

To identify the disease-causing mutation and to characterize penetrance and phenotypic variability in a large pedigree with episodic ataxia type 2 (EA-2) previously linked to chromosome 19.

BACKGROUND

Mutations in the CACNA1A gene on chromosome 19 encoding a calcium channel subunit cause EA-2, which is characterized by recurrent attacks of imbalance with interictal eye movement abnormalities.

METHODS

The authors used single-strand conformation polymorphism (SSCP) analysis to screen for point mutations, and direct sequencing to identify mutations in CACNA1A. Allele-specific oligonucleotides were designed to detect the presence of the diseased allele in members of their pedigree as well as in normal control subjects.

RESULTS

Reassessment of members of the pedigree revealed two notable clinical features. Diffuse weakness during attacks of ataxia was a prominent complaint. Two affected individuals had had episodic hemiplegia, one with typical migraine headaches. SSCP analysis revealed aberrant bands in exon 29 in affected members but not in normal control subjects. Direct sequencing of exon 29 identified a C-to-T change at position 4914 of the coding sequence of CACNA1A, predicting an early stop code at codon 1547. Two asymptomatic mutation carriers demonstrated the incomplete penetrance of this mutation.

CONCLUSIONS

A nonsense mutation in CACNA1A causes episodic ataxia and complaint of weakness, and may be associated with hemiplegia.

Modulation of the age at onset of Parkinson's disease by apolipoprotein E genotypes

Parkinson's disease (PD) patients often develop dementia, and Alzheimer's disease (AD) patients frequently develop parkinsonian signs. The apolipoprotein E epsilon4 allele is associated with increased risk and earlier onset of AD. We studied 137 unrelated white PD patients. Those with epsilon4 had the earliest onset (52.7 +/- 9.8 years), epsilon3/epsilon3 patients had an intermediate onset (56.1 +/- 11.1 years), and those with epsilon2 had the latest onset (59.1 +/- 13.4 years). The age at onset distribution for epsilon4/epsilon- was significantly earlier than for epsilon3/epsilon3 and epsilon2/epsilon3. These preliminary results suggest that apolipoprotein E genotypes modulate the age at onset of PD.

Effects of dopamine on postural control in parkinsonian subjects: scaling, set, and tone

1. This study investigates the effects of parkinsonism and of dopamine replacement therapy (levodopa) on scaling the magnitude of automatic postural responses based on sensory feedback and on predictive central set. Surface reactive torques and electromyographic (EMG) activity in response to backward surface translations were compared in patients with parkinsonism ON and OFF levodopa and in elderly control subjects. Correlations between the earliest postural responses [initial rate of change of torque and integrated EMG (IEMG)] and translation velocity provided a measure of postural magnitude scaling using somatosensory feedback. Correlations of responses with expected translation amplitude provided a measure of scaling dependent on predictive central set because the responses preceded amplitude completion. 2. Parkinsonian EMG responses in six leg and trunk muscles were not later than in elderly control subjects. In fact, quadriceps antagonist latencies were earlier than normal, resulting in coactivation at the knee not present in control subjects. EMG activation was fragmented, with short burst durations and high tonic levels that often returned to baseline with multiple bursts. In addition, parkinsonian responses showed smaller-than-normal agonist extensor bursts and larger-than-normal activation in tibialis and rectus femorus antagonist flexors. 3. Although parkinsonian subjects scaled postural responses to both displacement velocities and amplitudes, their torque response were smaller than those of elderly controls, especially in response to the largest displacement amplitudes. The gain (slope) of postural response magnitude scaling to displacement velocity was similar for parkinsonian and control subjects, although parkinsonian subjects had smaller torques. Parkinsonian subjects were also able to use prediction to scale responses to small expected displacement amplitudes, but many patients did not generate the larger plantarflexion torques required at larger displacement amplitudes. Reduced torque at large amplitudes was associated with less agonist gastrocnemius IEMG, increased tibialis antagonist burst responses, and increased tibialis tonic background activity. 4. Levodopa further reduced the already low magnitude of initial torque and IEMG responses to displacement velocities and amplitudes in parkinsonian patients. The ability to scale postural responses to velocity feedback was not affected by levodopa, but the ability to scale responses to large displacement amplitudes based on central set was worsened by levodopa. Levodopa also significantly reduced the tonic, background levels of EMG, particularly the distal gastrocnemius and tibialis activity. 5. High baseline muscle tone was apparent in parkinsonian subjects from their high background EMG activity in quiet stance, especially in tibialis and quadriceps, and the slow initial velocity of center of mass falling in response to displacements. By reducing tone, levodopa reduced passive stiffness to perturbations without increasing EMG burst magnitudes, resulting in less resistance to external displacements and thus faster center of body mass (COM) displacements. 6. The biggest postural deficit in parkinsonian subjects was not in response latency, pattern, or reactive or predictive scaling of response magnitude, but in quickly generating an adequate level of postural force. Dopamine improved tonic background postural tone but further weakened automatic postural responses to external displacements. Thus the basal ganglia may participate in postural control by regulating appropriate levels of background postural tone and by enabling adequate force generation for resisting external displacements.

Levodopa reduces muscle tone and lower extremity tremor in Parkinson's disease

OBJECTIVE

We have quantified the effects of levodopa treatment in Parkinsonian subjects during maintained stance.

METHODS

Electromyographic muscle activity during quiet stance was assessed in subjects with Parkinson's disease, who exhibited a fluctuating response to levodopa, and in age-matched control subjects. Stance stability was also assessed from mean displacement and velocity of the center of pressure excursions during stance.

RESULTS

Lower extremity and trunk muscles showed high amplitude activity in all Parkinson's subjects when "off", and a 4-5 Hz tremor in three of these subjects. When "on", the amplitude of muscle activity was reduced in the distal muscles more than the proximal, while tremor was suppressed in all muscles. Corresponding to the excessive muscle activity, the Parkinson's subjects had increased velocity and variability of velocity in the anterior-posterior center of foot pressure excursions, but the mean displacement of the center of pressure excursion was not different from the controls. The velocity of center of pressure excursions in the Parkinson's subjects "on", approached those of the control subjects suggesting that the excessive distal muscle amplitude and tremor contributed to the high velocity of the center of pressure.

CONCLUSIONS

These findings suggest that dopaminergic systems are involved in the regulation of muscle tone during stance. Depletion of dopaminergic transmission results in increased muscle tone and tremor in the lower extremities which may contribute to changes in posture and stability.

No evidence for association of familial Parkinson's disease with CAG repeat expansion

In some kindreds, familial Parkinson's disease (PD) exhibits genetic anticipation. Thus, we postulated that familial PD in certain kindreds may be associated with a CAG repeat expansion. However, using the repeat expansion detection method, we found no significant increase in the frequency of CAG repeat expansion among 46 unrelated PD probands compared with controls. Nor did we find evidence for CAG repeat expansion between generations in 11 different PD families that exhibit anticipation in age at onset.

Genetic anticipation in Parkinson's disease

We studied age at onset and family history of 137 patients (probands) with the diagnosis of idiopathic Parkinson's disease (PD). Probands (N = 21) who had an affected parent, aunt, or uncle were younger (p = 0.0001) at the onset of PD (47.7 +/- 8.8 years) than were probands (N = 11) who had an affected sib only (60.3 +/- 12.9 years) and probands (N = 105) who had no affected sib, parent, aunt, or uncle (59.2 +/- 11.4 years). Age at onset of affected family members differed significantly between generations (p = 0.0001). Age at onset was earlier, by an average of 17 years, in the proband generation than in the parental generation. The intrafamily variation in the calendar year of onset was too great to suggest a common point of exposure. Our data are most compatible with genetic anticipation, which could suggest involvement of an unstable trinucleotide repeat.

A gene for episodic ataxia/myokymia maps to chromosome 12p13

Episodic ataxia (EA) is a rare, familial disorder producing attacks of generalized ataxia, with normal or near-normal neurological function between attacks. Families with autosomal dominant EA represent at least two distinct clinical syndromes. One clinical type of EA (MIM 160120) includes individuals who have episodes of ataxia and dysarthria lasting seconds to minutes. In addition, myokymia (rippling of muscles, diagnosable by electromyography) is evident during and between attacks. Since K+ channel genes are candidate genes for EA, we tested markers near known K+ channel genes for linkage. Using a group of Genethon markers from one such region--chromosome 12p--we found evidence of linkage in four EA/myokymia families. A maximum combined lod score of 13.6 was obtained at theta = 0, with the marker D12S99. A human Ca++ channel gene, CACNL1A1, and three human K+ channel genes--KCNA5, KCNA6, and KCNA1--map close to D12S99, but the Ca++ channel gene is unlikely to be the site of the defect, because crossovers have been observed to occur between the disease gene and a CA-repeat marker located close to this gene. Studies of a large EA family with a different clinical phenotype (MIM 108500), which lacks myokymia but is associated with nystagmus, have excluded the gene causing that disease from the chromosome 12p locus.

Increased risk of Parkinson's disease in parents and siblings of patients

We studied the incidence of Parkinson's disease in 586 first-degree relatives (parents and siblings) of 114 randomly ascertained white patients with idiopathic Parkinson's disease and in 522 first-degree relatives of 114 age-matched unrelated white control subjects. Sixteen percent of patients had a family history as compared to 4% of control subjects (p < 0.01). The age-specific cumulative incidence was higher in the first-degree relatives of patients than in the first-degree relatives of control subjects (p = 0.007). The age-adjusted odds ratio was 3.5 (95% confidence interval: 1.3-9.4; p = 0.014). These results suggest that genes contribute to the etiology of Parkinson's disease.

Impaired mesial frontal and putamen activation in Parkinson's disease: a positron emission tomography study

Selection of movement in normal subjects has been shown to involve the premotor, supplementary motor, anterior cingulate, posterior parietal, and dorsolateral prefrontal areas. In Parkinson's disease (PD), the primary pathological change is degeneration of the nigrostriatal dopaminergic projections, and this is associated with difficulty in initiating actions. We wished to investigate the effect of the nigral abnormality in PD on cortical activation during movement. Using C15O2 and positron emission tomography (PET), we studied regional cerebral blood flow in 6 patients with PD and 6 control subjects while they performed motor tasks. Subjects were scanned while at rest, while repeatedly moving a joystick forward, and while freely choosing which of four possible directions to move the joystick. Significant increases in regional cerebral blood flow were determined with covariance analysis. In normal subjects, compared to the rest condition, the free-choice task activated the left primary sensorimotor cortex, left premotor cortex, left putamen, right dorsolateral prefrontal cortex and supplementary motor area, anterior cingulate area, and parietal association areas bilaterally. In the patients with PD, for the free-choice task, compared with the rest condition, there was significant activation in the left sensorimotor and premotor cortices but there was impaired activation of the contralateral putamen, the anterior cingulate, supplementary motor area, and dorsolateral prefrontal cortex. Impaired activation of the medial frontal areas may account for the difficulties PD patients have in initiating movements.

Time interval between repeated injections conditions the duration of motor improvement to apomorphine in Parkinson's disease

Behavioral hyposensitivity to repeated apomorphine administration occurs in fluctuating parkinsonian patients. To determine to what extent the interval between doses influences the response, we administered equal paired apomorphine injections to 10 fluctuating parkinsonian patients. Subjects received two apomorphine injections at 2-hour and at 4-hour intervals on different days after a 10- to 12-hour overnight period without levodopa. Following apomorphine doses at 2-hour intervals, the duration of response was reduced by 40% (61 versus 42 minutes, p less than 0.001) but was of equal duration when the doses were given at 4-hour intervals. These findings indicate that the interval between doses is a critical determinant of motor response. We postulate a time-dependent period of partial hyposensitivity to pulsatile DA stimulation.

Combination of dynamic and integral methods for generating reproducible functional CBF images

A new method to measure regional CBF is presented, applying both dynamic and integral analyses to a dynamic sequence of positron emission tomographic scans collected during and following the administration of H2(15)O (inhalation of C15O2). The dynamic analysis is used to correct continuously monitored arterial whole-blood activity for delay and dispersion relative to tissue scans. An integral analysis including corrections for this delay and dispersion is then used to calculate CBF on a pixel-by-pixel basis. Normal values and reproducibility over a 2-h period are presented, together with the results of validation and simulation studies. The results indicate that the single-tissue compartment model adequately describes the distribution of H2(15)O in the brain, without recourse to postulating a nonexchanging water pool.

Monozygotic twins with Parkinson's disease

A pair of monozygotic twins concordant for Parkinson's disease are described. The issue of genetic factors in Parkinson's disease is discussed.

Twin study of Parkinson disease

Zero concordance for Parkinson disease was found in the first 12 monozygotic twin pairs examined in an ongoing twin study. One co-twin (subject without Parkinson disease) had essential tremor, another had cerebral vascular disease, and a third was an alcoholic. Cigarette smoking appeared to be less frequent in the probands than in the co-twins (11.9 versus 16.1 pack-years). There was also evidence of premorbid personality differences between probands and co-twins dating back to late adolescence or early adult years. These preliminary findings suggest that genetic factors do not play a major role in the etiology of Parkinson disease and point to a prodromal onset of the disease as early as late adolescence or early adult life.

Treatment of Parkinson's disease with sodium valproate: clinical, pharmacological, and biochemical observations

Because there is biochemical evidence of decreased GABAergic function in Parkinson's disease, sodium valproate, an inhibitor of GABA catabolism, was administered to eight Parkinsonian patients. Valproate treatment did not significantly alter any Parkinsonian feature, but tended to increase the dyskinesia in the "on-off" patients. The increased dyskinesias were not a result of altered peripheral metabolism of L-dopa. Despite obtaining high plasma levels of valproate, no consistent alteration of CSF GABA levels could be demonstrated. Thus, in these patients, an effect of valproate on GABA metabolism is unproven, and in turn, the role of GABA in Parkinsonism and dyskinesia uncertain.

Thyroid-stimulating immunoglobulins and the control of thyroid function

Triiodothyronine (T3) suppression and thyrotropin-releasing hormone (TRH) tests were used to study thyroid function in 50 patients with thyroid disease. The results of the thyroid function tests were compared with the levels of serum thyroid-stimulating immunoglobulins (TSI) measured by a radio-receptor assay. In euthyroid and hyperthyroid patients, the presence of TSI corresponded with the absence of TSH control of thyroid function. However, in two hypothyroid patients with serum TSI levels readily detectable in the receptor assay, T3 suppression and TRH tests indicated that thyroid function was under TSH control.

Neonatal hyperthyroidism and long-acting thyroid stimulator protector

Neonatal hyperthyroidism has been thought to result from transplacental passage of long-acting thyroid stimulator (L.A.T.S.) from a mother with Graves's disease. A case is presented here in which no L.A.T.S. was detected in the mother or neonate but another immunoglobulin, L.A.T.S. protector, a specific human thyroid stimulator, was shown to be present in the mother's serum. This stimulator may have been the cause of the neonatal hyperthyroidism.

A modified bioassay for thyroid-stimulating hormone and long-acting thyroid stimulator

After iodine depletion of mice, the time needed for the bioassay of long-acting thyroid stimulator (LATS) and thyroid-stimulating hormone (TSH) can be shortened to allow the completion of two assays per week. Suppression of mouse TSH with 0·1 μg tri-iodothyronine was necessary in the TSH assay and with 5 μg thyroxine in the LATS assay. These can be administered as a single i.p. injection with the 131I. The response of the assay mice to TSH can be improved by giving theophylline (0·5 mg) just before, with and after the stimulus.