Correction to: High-throughput method for ear phenotyping and kernel weight estimation in maize using ear digital imaging.

[This corrects the article DOI: 10.1186/s13007-018-0317-4.].

Subtropical Marine Low Stratiform Cloud Deck Spatial Errors in the E3SMv1 Atmosphere Model.

Marine low-level clouds continue to be poorly simulated in models despite many studies and field experiments devoted to their improvement. Here we focus on the spatial errors in the cloud decks in the Department of Energy Earth system model (the Energy Exascale Earth System Model [E3SM]) relative to the satellite climatology by calculating centroid distances, area ratios, and overlap ratios. Since model dynamics is better simulated than clouds, these errors are attributed primarily to the model physics. To gain additional insight, we performed a sensitivity run in which model winds were nudged to those of reanalysis. This results in a large change (but not necessarily an improvement) in the simulated cloud decks. These differences between simulations are mainly due to the interactions between model dynamics and physics. These results suggest that both model physics (widely recognized) and its interaction with dynamics (less recognized) are important to model improvement in simulating these low-level clouds.

High-throughput method for ear phenotyping and kernel weight estimation in maize using ear digital imaging.

BACKGROUND: Grain yield, ear and kernel attributes can assist to understand the performance of maize plant under different environmental conditions and can be used in the variety development process to address farmer's preferences. These parameters are however still laborious and expensive to measure. RESULTS: A low-cost ear digital imaging method was developed that provides estimates of ear and kernel attributes i.e., ear number and size, kernel number and size as well as kernel weight from photos of ears harvested from field trial plots. The image processing method uses a script that runs in a batch mode on ImageJ; an open source software. Kernel weight was estimated using the total kernel number derived from the number of kernels visible on the image and the average kernel size. Data showed a good agreement in terms of accuracy and precision between ground truth measurements and data generated through image processing. Broad-sense heritability of the estimated parameters was in the range or higher than that for measured grain weight. Limitation of the method for kernel weight estimation is discussed. CONCLUSION: The method developed in this work provides an opportunity to significantly reduce the cost of selection in the breeding process, especially for resource constrained crop improvement programs and can be used to learn more about the genetic bases of grain yield determinants.

Mass spectrometric analysis of unknown haemoglobin fractions identified by high-performance liquid chromatography in an antenatal screening programme.

AIMS: The majority of haematology laboratories use automated high-performance liquid chromatography (HPLC) as a primary method in the screening of samples for haemoglobin variants and thalassaemia. HPLC detects adducted fractions, such as HbA1C and other peaks of unknown significance. The National Health Service (NHS) Sickle and Thalassaemia Screening Programme does not mandate further assessment of these unknown peaks, but their presence may cause concern or precipitate detailed investigations. Mass spectrometry (MS) is being increasingly used in NHS Laboratories and is an effective method of characterising variant haemoglobins. METHOD: Antenatal blood samples accepted for NHS Sickle and Thalassaemia Screening Programme from 2005 to 2013 were assessed. Those samples with unidentified peaks on HPLC were further analysed by Liquid chromatography tandem MS (LCMSMS). RESULTS: 58,493 samples were processed. 966 (1.6%) significant haemoglobinopathies were identified. 68 patients (0.11%) were found to have unidentified peaks on HPLC. α chain variants: two were hyperunstable α variants, Hb Adana and Hb H/Constant Spring. The patient with HbH/Constant Spring required transfusion during pregnancy. Other abnormalities include 24 unstable α chain variants of minimal clinical significance and 17 α chain variants of no clinical significance. The frequency of ß chain abnormalities was lower, with 10 patients having an insignificant ß chain variant, 4 mildly unstable ß chain variants (2 of whom had increased oxygen affinity) and 4 with variants associated with increased oxygen affinity. CONCLUSIONS: The prevalence of unidentified variants on automated HPLC within our population is 0.1%. LCMSMS is an effective technique to assist in the characterisation of unknown haemoglobin variants. α chain variants of limited clinical significance were the most commonly detected abnormality.

Motor planning ability is not related to lesion side or functional manual ability in children with hemiplegic cerebral palsy.

Optimal task performance requires anticipatory planning to select the most appropriate movement strategy. There is conflicting evidence for hemispheric specialisation of motor planning, with some suggesting left hemisphere dominance, claiming that children with right hemiplegic cerebral palsy (HCP) are therefore disproportionally affected. An alternative view is that there is a positive relationship between functional ability (rather than side of lesion) and motor planning skill. We aimed to compare children with right and left HCP on motor planning ability and to explore its relationship with functional manual ability. Participants were 76 children with HCP (40 left HCP; 30 female), aged 4-15 years (Mean 9.09, SD 2.94). Motor planning was assessed using a measure of end-state comfort, which involved turning a hexagonal handle 180° without readjusting grasp. This is difficult, or in some cases impossible, to achieve unless an appropriate initial grasp is adopted. Children completed 24 turns (12 clockwise), which were video recorded for offline scoring. Functional manual ability was assessed with the ABILHAND-Kids questionnaire, completed by parents. Contrary to the existing literature, no differences were observed between right and left HCP. However, a significant interaction between direction of turn and side of hemiplegia indicated a preferential bias for turns in the medial direction, consistent with the "medial over lateral advantage". There was no relationship between functional ability and motor planning. Therefore, motor planning may not be a priority for therapeutic intervention to improve functional ability in HCP.

The myth of the 'unaffected' side after unilateral stroke: is reorganisation of the non-infarcted corticospinal system to re-establish balance the price for recovery?

BACKGROUND: Bilateral changes in the hemispheric reorganisation have been observed chronically after unilateral stroke. Our hypotheses were that activity dependent competition between the lesioned and non-lesioned corticospinal systems would result in persisting asymmetry and be associated with poor recovery. METHODS: Eleven subjects (medium 6.5 years after stroke) were compared to 9 age-matched controls. The power spectral density (PSD) of the sensorimotor electroencephalogram (SM1-EEG) and electromyogram (EMG) and corticomuscular coherence (CMC) were studied during rest and isometric contraction of right or left opponens pollicis (OP). Global recovery was assessed using NIH score. FINDINGS: There was bilateral loss of beta frequency activity in the SM1-EEGs and OP-EMGs in strokes compared to controls. There was no difference between strokes and controls in symmetry indices estimated between the two corticospinal systems for SM1-EEG, OP-EMG and CMC. Performance correlated with preservation of beta frequency power in OP-EMG in both hands. Symmetry indices for the SM1-EEG, OP-EMG and CMC correlated with recovery. INTERPRETATION: Significant changes occurred at both cortical and spinomuscular levels after stroke but to the same degree and in the same direction in both the lesioned and non-lesioned corticospinal systems. Global recovery correlated with the degree of symmetry between corticospinal systems at all three levels - cortical and spinomuscular levels and their connectivity (CMC), but not with the absolute degree of abnormality. Re-establishing balance between the corticospinal systems may be important for overall motor function, even if it is achieved at the expense of the non-lesioned system.

Corticospinal tract development and its plasticity after perinatal injury.

The final pattern of the origin and termination of the corticospinal tract is shaped during development by the balance between projection and withdrawal of axons. In animals, unilateral inhibition of the sensorimotor cortex during development results in a sparse contralateral projection from this cortex and retention of a greater number of ipsilateral projections from the more active cortex. Similarly in subjects with hemiplegic cerebral palsy if transcranial magnetic stimulation (TMS) of the damaged motor cortex fails to evoke responses in the paretic upper limb, TMS of the undamaged ipsilateral motor cortex evokes abnormally large and short-onset responses. Rather than representing a "reparative plasticity in response to injury", this review presents evidence that increased ipsilateral projections from the non-infarcted motor cortex arise from perturbation of ongoing developmental processes, whereby reduced activity in the damaged hemisphere, leads to increased withdrawal of its surviving contralateral corticospinal projections because their terminals have been displaced by the more active ipsilateral projections of the undamaged hemisphere and thereby adding to the degree of long-term motor impairment.

[The use of suprarenal scintigraphy in the differential diagnosis of suprarenal incidentaloma]. / Utilidad de la gammagrafía suprarrenal en el diagnóstico diferencial del incidentaloma suprarrenal.

OBJECTIVES: To assess the usefulness of adrenal scintigraphy for clinical evaluation of adrenal incidentalomas, and its relation with pathological diagnosis and follow-up. PATIENTS AND METHODS: We have studied 46 patients with unilateral adrenal incidentaloma of size between 10 and 100 mm (average 30.5 +/- 19 mm). The lesions were discovered with abdominal computerized tomography in the study of a primary tumor (22%) or in the evaluation of benign pathology (78%). Adrenal scintigraphy assessed uptake in adrenal incidentaloma. Hormonal study included urinary catecholamines, plasma cortisol after dexamethasone, adrenal androgens, and renin and aldosterone in hypertensive patients. Five patients were operated, FNAB was carried out in three patients, and in the rest average follow-up was 29 +/- 21 months. Adrenal incidentaloma was considered nonfunctional if the lesion did not modified its size nor showed analytical alterations along a follow-up higher than 8 months. RESULTS: Of 46 adrenal lesions, seven didn't show uptake (three metastases, one cyst, one adrenal carcinoma, one pheochromocytoma, and one angiomyolipoma), 34 showed excessive uptake (29 nonfunctional adrenal nodules and 5 hyperfunctional adrenal nodules), and five had normal uptake (nonfunctional adrenal nodules). Adrenal scintigraphy was compatible in all cases with cytological study or the response to chemotherapy. Along the follow-up, growth of the lesion was demonstrated in 23%, and reduction or disappearance of the lesion in 11%, with no hormonal significant changes. CONCLUSIONS: Detection of a lesion with no uptake in adrenal scintigraphy forces to carry out complementary explorations in order to rule out malignant pathology. A lesion with excessive uptake is indicative of a benign process and should be assessed with hormonal determinations.

Utilidad de la gammagrafía suprarrenal en el diagnóstico diferencial del incidentaloma suprarrenal / Role of adrenal scintigraphy in the management of adrenal incidentaloma

Objetivos. Valorar la utilidad de la gammagrafía suprarrenal en el estudio de los incidentalomas suprarrenales y su relación con el diagnóstico patológico y el seguimiento posterior. Pacientes y métodos. Hemos estudiado 46 pacientes con incidentaloma suprarrenal unilateral de tamaño entre 10 y 100 mm (media: 30,5 ± 19 mm). Las lesiones se localizaron mediante tomografía computarizada abdominal durante el estudio de un tumor primario (22%) o de patología benigna (78%). La gammagrafía suprarrenal valoró la existencia o no de captación en el incidentaloma suprarrenal. El estudio hormonal incluyó catecolaminas urinarias, cortisol plasmático tras dexametasona, andrógenos adrenales y renina y aldosterona en pacientes hipertensos. Cinco pacientes fueron operados, en tres se realizó punción-aspiración con aguja fina y en los restantes seguimiento medio de 29 ± 21 meses. Se consideró incidentaloma suprarrenal no funcionante si la lesión no modificaba su tamaño ni mostraba alteraciones analíticas en el seguimiento superior a 8 meses. Resultados. De las 46 lesiones suprarrenales 7 fueron hipocaptadoras (tres metástasis, un quiste, un carcinoma suprarrenal, un feocromocitoma y un angiomiolipoma), 34 hipercaptadoras (29 nódulos suprarrenales no funcionantes y 5 hiperfuncionantes) y 5 normocaptadoras (nódulos suprarrenales no funcionantes). La gammagrafía suprarrenal fue concordante con estudio citológico o la respuesta a quimioterapia en todos los casos. Durante el seguimiento se demostró un crecimiento de la lesión en el 23% y reducción o desaparición de las lesiones en el 11% y no se encontraron cambios significativos hormonales.Conclusiones. Una lesión hipocaptadora en gammagrafía suprarrenal hace necesaria la realización de exploraciones complementarias para descartar patología maligna. Una lesión hipercaptadora es indicativa de proceso benigno y debe ser valorada con determinaciones hormonales

Objetives. To assess the usefulness of adrenal scintigraphy for clinical evaluation of adrenal incidentalomas, and its relation with pathological diagnosis and follow-up. Patients and methods. We have studied 46 patients with unilateral adrenal incidentaloma of size between 10 and 100 mm (average 30.5 ± 19 mm). The lesions were discovered with abdominal computerized tomography in the study of a primary tumor (22%) or in the evaluation of benign pathology (78%). Adrenal scintigraphy assessed uptake in adrenal incidentaloma. Hormonal study included urinary catecholamines, plasma cortisol after dexamethasone, adrenal androgens, and renin and aldosterone in hypertensive patients. Five patients were operated, FNAB was carried out in three patients, and in the rest average follow-up was 29 ± 21 months. Adrenal incidentaloma was considered nonfunctional if the lesion did not modified its size nor showed analytical alterations along a follow-up higher than 8 months. Results. Of 46 adrenal lesions, seven didn't show uptake (three metastases, one cyst, one adrenal carcinoma, one pheochromocytoma, and one angiomyolipoma), 34 showed excessive uptake (29 nonfunctional adrenal nodules and 5 hyperfunctional adrenal nodules), and five had normal uptake (nonfunctional adrenal nodules). Adrenal scintigraphy was compatible in all cases with cytological study or the response to chemotherapy. Along the follow-up, growth of the lesion was demonstrated in 23%, and reduction or disappearance of the lesion in 11%, with no hormonal significant changes. Conclusions. Detection of a lesion with no uptake in adrenal scintigraphy forces to carry out complementary explorations in order to rule out malignant pathology. A lesion with excessive uptake is indicative of a benign process and should be assessed with hormonal determinations

Plastic surgery senior house officers in the UK and Ireland: academic background, publication rates and research plans.

Academic achievements by surgical trainees may vary according to the competitiveness of the subspecialty and desirability of the consultant post. Plastic and reconstructive surgery is a competitive specialty. In order to assess the level of achievement of current trainees, we investigated the academic qualifications, publication rates and future research plans of 100 senior house officers in plastic surgery working in units in the United Kingdom and Ireland. Selected results from our survey show that 30% had intercalated degrees, 6% had higher degrees, 58% of trainees had MRCS, 37% had previous plastic surgery experience and 57% had published (range 1-13). We believe this study provides interesting information concerning the current crop of plastic surgery trainees in the United Kingdom and Ireland. This survey may provide a benchmark for consultants to refer to when shortlisting for SHO posts. We also believe it will be of interest to those junior trainees hoping to pursue a career in plastic surgery.

Evidence of activity-dependent withdrawal of corticospinal projections during human development.

OBJECTIVE: To characterize the development of ipsilateral corticospinal projections from birth and compare to 1) development of contralateral projections in the same subjects and 2) ipsilateral corticospinal projections in subjects with unilateral lesions of the corticospinal system acquired perinatally or in adulthood. METHOD: Transcranial magnetic stimulation excited the motor cortex, and responses were recorded bilaterally in pectoralis major, biceps brachii, and the first dorsal interosseus muscles. Subjects studied included 9 neonates recruited at birth, studied longitudinally for 2 years; 85 healthy subjects aged from birth to adulthood; 10 subjects with hemiplegic cerebral palsy; and 8 with hemiplegia after stroke. RESULTS: In neonates, ipsilateral responses had significantly shorter onsets than contralateral responses but similar thresholds and amplitudes. Thresholds within both pathways increased in the first 3 months. Differential development was present from 3 months so that by 18 months ipsilateral responses were significantly smaller and had significantly higher thresholds and longer onset latencies than contralateral responses. A similar pattern of smaller and later ipsilateral responses was observed after transcranial magnetic stimulation of the intact cortex in subjects with stroke. In contrast, subjects with hemiplegic cerebral palsy had ipsilateral responses with onsets, thresholds and amplitudes similar to those of contralateral responses. Significant branching of contralateral corticospinal axons from the intact motor cortex was excluded by cross-correlation analysis. CONCLUSIONS: These data, together with previously published anatomic and radiologic studies, are consistent with activity-dependent corticospinal axonal withdrawal during development and maintenance of increased corticomotoneuronal projections from the intact hemisphere after unilateral perinatal lesions.

Abnormal corticospinal function but normal axonal guidance in human L1CAM mutations.

L1 cell adhesion molecule (L1CAM) gene mutations are associated with X-linked 'recessive' neurological syndromes characterized by spasticity of the legs. L1CAM knock-out mice show hypoplasia of the corticospinal tract and failure of corticospinal axonal decussation and projection beyond the cervical spinal cord. The aim of this study was to determine if similar neuropathology underlies the spastic diplegia of males hemizygous for L1CAM mutations. Studies were performed on eight carrier females and 10 hemizygous males. Transcranial magnetic stimulation excited the corticospinal tract and responses were recorded in biceps brachii and quadriceps femoris. In contralateral biceps and quadriceps the responses had high thresholds and delayed onset compared with normal subjects. Ipsilateral responses in biceps were smaller, with higher thresholds and delayed onsets relative to contralateral responses. Subthreshold corticospinal conditioning of the stretch reflex of biceps and quadriceps was abnormal in both hemizygous males and carrier females suggesting there may also be a reduced projection to inhibitory interneurones. Histological examination of post-mortem material from a 2-week-old male with an L1CAM mutation revealed normal corticospinal decussation and axonal projections to lumbar spinal segments. These data support a role for L1CAM in corticospinal tract development in hemizygous males and 'carrier' females, but do not support a critical role for L1CAM in corticospinal axonal guidance.

Integrins regulate the intracellular distribution of eukaryotic initiation factor 4E in platelets. A checkpoint for translational control.

Recent evidence from our laboratory demonstrates that platelets synthesize numerous proteins in a signal-dependent fashion (Pabla, R., Weyrich, A. S., Dixon, D. A., Bray, P. F., McIntyre, T. M., Prescott, S. M., and Zimmerman, G. A. (1999) J. Cell Biol. 144, 175-184; Weyrich, A. S., Dixon, D. A., Pabla, R., Elstad, M. R., McIntyre, T. M., Prescott, S. M., and Zimmerman, G. A. (1998) Proc. Natl. Acad. Sci. U. S. A. 95, 5556-5561). Protein synthesis in platelets is controlled at the translational level; however, the mechanisms of regulation are not known. Here we demonstrate that translation initiation factors are redistributed to mRNA-rich areas in aggregated platelets, an event that induces protein synthesis. Interrogation of cDNA arrays revealed that platelet-derived mRNAs are primarily associated with the cytoskeletal core. In contrast, eukaryotic initiation factor 4E (eIF4E), the essential mRNA cap-binding protein that controls global translation rates, is localized in the membrane skeleton and soluble fraction of platelets, physically separated from most mRNAs. Platelet activation redistributes eIF4E to the cytoskeleton and increases interactions of eIF4E with mRNA cap structures. Redistribution of eIF4E to the mRNA-rich cytoskeleton coincides with a marked increase in protein synthesis, a process that is blocked when intracellular actin is disrupted. Additional studies demonstrated that beta(3) integrins are the primary membrane receptor that distributes eIF4E within the cell. These results imply that integrins link receptor-mediated pathways with mRNA-rich cytoskeletal domains and thereby modulate the organization of intracellular translational complexes. They also indicate that the functional status of eIF4E is regulated by its intracellular distribution.

Intracranial migration of halo fixation pins: a complication of using an extraoral distraction device.

OBJECTIVE: Distraction osteogenesis is a well-accepted technique in the treatment of patients with hypoplastic craniofacial components. Complications of distraction osteogenesis are well described in the literature. We describe a complication of using an external distraction device in a 9-year-old girl with Pfeiffer. INTERVENTION AND RESULTS: A modified Lefort III osteotomy was performed for maxillary hypoplasia with application of an external distraction halo device by a pediatric neurosurgeon. A postoperative computed tomography (CT) scan showed 0.5-cm skull penetration of the cranial pins. The pins were repositioned and the patient was followed up on a regular basis until discharge from the hospital. At 3-week follow-up, a CT scan of the head showed migration of the pins 1.5 cm intracranially. The halo was removed and repositioned at a different site. No detectable neurological sequelae from the pin penetration were noted. The patient developed cellulitis at the site of the penetration and was admitted to the hospital for a course of intravenous antibiotics. There were no other complications, and the rest of her treatment course proceeded as planned. A review of the literature on complications of halo usage as well as suggestions for their management in association with distraction osteogenesis is described.

Comparison of spinal myotatic reflexes in human adults investigated with cross-correlation and signal averaging methods.

A cross-correlation method for recording spinal myotatic reflexes has been developed to meet the need for brief test periods in babies and children and subjects with central neurological pathology. In normal adult subjects the method has been validated by comparing excitatory and inhibitory reflexes obtained with cross-correlation with those obtained with conventional signal averaging. In the cross-correlation method a pseudo-random binary sequence of 64 brief tendon taps was delivered in <1.5 s, and in the averaging method 20-150 taps at one per second. The reflexes were expressed as unit impulse responses to enable direct, quantitative comparisons to be made. With cross-correlation the responses were slightly expanded in time, had lower peak amplitudes, and onset latencies advanced by 10 ms, the clock period of the pseudo-random binary sequence. The amplitude of biceps phasic stretch reflex increased with muscle contraction in a similar manner with both methods. In tests for stationarity the amplitude of biceps phasic stretch reflex varied <10% in the first six repeats of the pseudo-random binary sequence. The tap force required at threshold for cross-correlation was approximately half that for averaging, but with both methods the magnitude of biceps phasic stretch reflex varied linearly with tap force over the range of one to two times threshold. The validity of responses obtained with cross-correlation was assessed by a statistical procedure. In conclusion, the cross-correlation method is robust and gives similar results to those obtained with averaging.

Reciprocal and Renshaw (recurrent) inhibition are functional in man at birth.

The aims were (1) to determine when in human postnatal development Group Ia reciprocal and Renshaw inhibition can be demonstrated; (2) to explore the relationship between the expression reciprocal inhibition and the disappearance of Group Ia excitatory reflexes between agonist and antagonist muscles. Studies were performed on 99 subjects, aged 1 day to 31 years, of whom 53 were neonates. A longitudinal study was also performed on 29 subjects recruited at birth and studied 3 monthly until 12 months of age. Reciprocal inhibitory and excitatory reflexes were recorded in the surface EMG of contracting biceps brachii (Bi), evoked by taps applied to the tendon of triceps brachii (Tri). Reciprocal excitatory reflexes were recorded in all but one neonate. Reciprocal inhibition was observed in 25% of neonates; evidence is provided that it was likely to have been masked by low threshold reciprocal excitation in the remaining neonates. Reciprocal inhibition was demonstrated in all subjects after 9 months of age. In four neonates there was depression of inhibition of Bi during co-contraction of Bi and Tri implying that Group Ia interneurones may be under segmental and suprasegmental control at birth. Renshaw cells, identified in human postmortem cervical spinal cord by their morphology, location and calbindin D28K immunoreactivity, were present at 11 weeks post-conceptional age (PCA) and by 35 weeks PCA had mature morphological characteristics. In four neonates reciprocal inhibitory responses in Bi disappeared when the tap to Tri evoked its own homonymous phasic stretch reflex, providing neurophysiological evidence for Renshaw inhibition of Group Ia inhibitory interneurones.

Short latency heteronymous excitatory and inhibitory reflexes between antagonist and heteronymous muscles of the human shoulder and upper limb.

The aims were (i) to investigate heteronymous excitatory and inhibitory Group Ia reflexes linking agonist/antagonist muscle pairs acting at the shoulder and elbow; clavicular pectoralis major (Pmajor) and posterior deltoid (Pdeltoid); biceps brachii (Bi) and Tri brachii (Tri), and linking muscles acting at the elbow (Bi and Tri) with muscles acting at the shoulder (Pmajor and Pdeltoid). (ii) To test the hypothesis that the excitability of the reflexes would vary between different tasks in a functionally relevant manner. The study was performed on 45 adults. Reflexes were recorded in the surface EMG when the target muscle was contracting at 10% maximum voluntary contraction. Reflexes were recorded in Bi and Tri with the elbow joint in one of three positions: 105 degrees, 80 degrees, or 55 degrees from full extension. Group Ia reflexes were evoked using a small, brief tap to the tendon of the muscle being stimulated. Reflexes were recorded by cross-correlation of the surface EMG and pseudo-random series of taps. All subjects demonstrated short latency inhibition and excitation between agonist/antagonist muscle pairs; inhibition was significantly more frequent than excitation. Excitation and inhibition occurred with equal frequency between muscle pairs acting between elbow and shoulder. Minimum central delays for excitatory reflexes were 1 ms, consistent with monosynaptic projections and for inhibitory responses were 2 ms consistent with disynaptic linkage. Later excitatory and inhibitory reflexes with central delays of up to 15 ms also occurred. The probability of evoking excitation or inhibition in Tri or Bi changed with the different elbow positions.

[Cerebral perfusion during word repetition in epileptic patients]. / Perfusión cerebral durante la repetición de palabras en pacientes epilépticos.

OBJECTIVE: To localize the cortical regions for language in patients who are to have brain surgery. PATIENTS AND METHODS: We made a SPECT (Single Photon Emission using Computerized Tomography) study of cerebral perfusion in 14 patients with drug-resistant temporal epilepsy who were candidates for brain surgery. The patients were selected consecutively from those attending for surgical assessment. We selected the patients in whom two 99mTc-HMPAO studies could be done in the same week: one without sensory stimulation and one whilst listening and repeating a series of ordinary words in fairly frequent use. The two studies were assessed qualitatively (on a 16 colour image scale, with a background subtraction of 20% and standardized to the point of maximum uptake). Changes were considered to be significant when a greater intensity of two colours was localized and semiquantitative (with regular areas of interest, of 4 x 4 pixels, placed on the region in which the qualitative change was observed and referenced to cerebellar activity). RESULTS: We found increased perfusion in the temporo-parietal regions in 11 of the 14 patients. In most (9/14 cases) this was bilateral and in two cases on the left only. We observed a certain predominant pattern: a bilateral increase in temporal perfusion, involving the more anterior regions of the left hemisphere and also the middle and posterior regions of the right hemisphere. The maximum percentage increase in perfusion on semiquantitative assessment was 12%. CONCLUSION: Although the changes seen may correspond to activation in the cortical regions related to different cerebral functions, we consider that with the SPECT technique one may detect changes in perfusion of the regions of the brain which are involved in language processing.