Evaluation of preventive tract embolization with standardized gelatin sponge slurry on chest tube placement rate after CT-guided lung biopsy: a propensity score analysis

BACKGROUND

To evaluate the effect of tract embolization (TE) with gelatin sponge slurries during a percutaneous lung biopsy on chest tube placement and to evaluate the predictive factors of chest tube placement.

METHODS

Percutaneous CT-guided lung biopsies performed with (TE) or without (non-TE) tract embolization or between June 2012 and December 2021 at three referral tertiary centers were retrospectively analyzed. The exclusion criteria were mediastinal biopsies, pleural tumors, and tumors adjacent to the pleura without pleural crossing. Variables related to patients, tumors, and procedures were collected. Univariable and multivariable analyses were performed to determine risk factors for chest tube placement. Furthermore, the propensity score matching analysis was adopted to yield a matched cohort.

RESULTS

A total of 1157 procedures in 1157 patients were analyzed, among which 560 (48.4%) were with TE (mean age 66.5 ± 9.2, 584 men). The rates of pneumothorax (44.9% vs. 26.1%, respectively; p < 0.001) and chest tube placement (4.8% vs. 2.3%, respectively; p < 0.001) were significantly higher in the non-TE group than in the TE group. No non-targeted embolization or systemic air embolism occurred. In the whole population, two protective factors for chest tube placement were found in univariate analysis: TE (OR 0.465 [0.239-0.904], p < 0.05) and prone position (OR 0.212 [0.094-0.482], p < 0.001). These data were confirmed in multivariate analysis (p < 0.001 and p < 0.0001 respectively). In the propensity matched cohort, TE reduces significatively the risk of chest tube insertion (OR = 0.44 [0.21-0.87], p < 0.05).

CONCLUSIONS

The TE technique using standardized gelatin sponge slurry reduces the need for chest tube placement after percutaneous CT-guided lung biopsy.

CRITICAL RELEVANCE STATEMENT

The tract embolization technique using standardized gelatin sponge slurry reduces the need for chest tube placement after percutaneous CT-guided lung biopsy.

KEY POINTS

1. Use of tract embolization with gelatine sponge slurry during percutaneous lung biopsy is safe. 2. Use of tract embolization significantly reduces the risk of chest tube insertion. 3. This is the first multicenter study to show the protective effect of tract embolization on chest tube insertion.

Brachytherapy boost in anal canal cancer - A GEC ESTRO PDR task force meta-analysis

Purpose

A meta-analysis is presented comparing clinical outcomes and toxicities between high dose rate (HDR) and pulsed dose rate (PDR) brachytherapy (BT) for anal cancer.

Methods and material

Retrospective or prospective clinical trials were identified on electronical databases. Data were collected per Preferred Reporting Items for Systematic Reviews and meta-Analyses guidelines. Pooled effect size for HDR and PDR BT were compared using subgroup analyses.

Results

Nine retrospective studies with a total of 481 patients treated were included of which 219 with HDR and 262 with PDR. Significant differences were observed between the two groups for baseline characteristics and treatment. The cumulative proportion of stage T3-T4 was lower in the HDR group, 0.15 [95 % confidence interval (CI) 0.07-0.29] vs 0.27 [95 %CI 0.09-0.57] in the LDR group, p < 0.001. Lower BT doses (in equivalent 2-Gy fraction dose) were given for patients in the HDR group, 11.9 Gy [95 %CI 8.2-15.5] vs 19.5 Gy [95 %CI 15.0-24.0] in the PDR group, p < 0.001. No significant differences were found for clinical outcomes or toxicities. The pooled effect size of the overall survival at 5 years for HDR and PDR was respectively 0.82 [95 %CI 0.70-0.94] and 0.82 [95 %CI 0.73-0.91], p > 0.99. The 5 years local control was 0.86 [95 % confidence interval (CI) 0.81-0.91] and 0.83 [95 %CI 0.77-0.89], p = 0.62. Cumulative toxicity-related colostomy proportion was 0.04 [95 %CI 0.02-0.09] and 0.03 [95 %CI 0.02-0.07], p = 0.85.

Conclusion

Both modalities provided a good profile of tolerance and are effective organ conservative strategies for patients with anal canal cancer. In parallel with ongoing developments to better determine the optimal fractionation and dose for HDR-BT treatments, especially in large tumors, PDR BT still has a crucial role for dose escalation strategy in advanced cases.

An ultra-low-dose protocol for computed tomography-guided lung radiofrequency ablations

To evaluate the safety and efficacy of ultra-low-dose (ULD) protocol for computed tomography (CT)-guided lung radiofrequency ablation (RFA). Patients who had undergone lung RFA between November 2017 and January 2021 were consecutively and retrospectively included. Thirty patients were treated using a conventional standard protocol (SP), including helical acquisitions with mA automatic adjustment and sequential CT at 80 kVp; and 31, with a ULD protocol defined with helical acquisitions with fixed mA and sequential series at 100 kVp. These parameters were selected from those used for a diagnostic lung low-dose CT scanner. Patient characteristics, dose indicators, technical efficacy (minimal margin [MM], recurrence during follow-up), and complications (pneumothorax, alveolar haemorrhage, and haemoptysis) were recorded. We included 61 patients (median age, 65 [54-73] and 33 women), with no significant differences according to the type of protocol, except for the type of anaesthesia. Even if the number of helical acquisitions did not significantly change, all dose indicators significantly decreased by 1.5-fold-3-fold. The median dose-length-product and effective dose, with their ranges, respectively, were 465 mGy cm (315-554) and 6.5 mSv (4.4-7.8) in the SP group versus 178 mGy cm (154-267) and 2.5 mSv (2.2-3.7) in the ULD group, (p< 001). The ULD group exhibited lower intraoperator variability and better interoperator alignment than those of the SP group. The MM was not significantly different between the two groups (4.6 mm versus 5 mm,p= 16). One local recurrence was observed in each group at 8 months in the SP and at one year in the ULD group (p= 1). The complication rates did not differ significantly. Implementing an ULD protocol during lung RFA may provide similar efficacy, a reduction of dose indicators, and intra- and interoperator variability, without increasing complication rates, compared to those associated with an SP.

Impact of fiducial markers placement on the delineation of target volumes in radiation therapy for oesophageal cancer: FIDUCOR study

Purpose

This prospective monocentric phase II study (FIDUCOR-study, NCT02526134) aimed to assess the impact of fiducial markers (FMs) implantation on conformal chemo-radiation therapy (CRT) planning in oesophageal carcinoma (EC) patients.

Methods/materials

Fifteen EC patients were enrolled in the study. Each patient underwent two simulation CT-scans before (CT1) and after (CT2) FMs implantation, in the same position. FMs (3 mm length gold markers, preloaded in a 22G needle) were implanted after sedation, under endoscopic ultrasound (EUS) and X-Ray guidance, and were placed at the tumor’s extremities, and in the visible lymph nodes. Target delineation and treatment plan were both performed first on CT1 with the assistance of diagnosis CT, gastroscopy and EUS details, and second on CT2 using FMs and CT-data. The value of FMs implantation was assessed by the difference of growth-tumor-volume (GTV) and clinical-target-volume (CTV) between CT1-based and CT2-based delineation. A significant difference was defined as a ≥5 mm-difference on axial(x) or coronal(y) slices, a ≥10mm-difference on sagittal slices, or a ≥20%-difference in GTV. The impact on dose distribution in organs at risk (OAR) (lung, heart, liver) was also studied.

Results

Between 09/2014 and 12/2015, 15 patients could achieve fiducial procedures, without any complication. One FM migration occurred. We observed a significant modification of the GTV-dimension in 100% of the cases (15/15, 95%CI: [78.2;100.0]), mainly due to a difference in sagittal dimension with a mean variation of 11.2 mm and a difference&gt; 10 mm for 8/15 patients (53.3%). One patient had a significant isocenter displacement as high as 20 mm. The oesophagus tumor was not seen on the CT-scan in one patient due to its small size. One patient had a distant lymph node metastasis not visible on CT-scan. We observed no significant impact on OAR distribution.

Conclusion

In our study, FMs-implantation under EUS had a positive impact on accurate volume definition in EC-patients (modification of GTV in 15/15 patients). Close cooperation between gastroenterologist and radiation oncologist has the potential to improve local treatment of oesophageal carcinoma.

Predictors of long term tricuspid regurgitation after pulmonary valve replacement: a single center study on the cohort of significant preoperative tricuspid regurgitation

Background

Almost one-third of repaired tetralogy of Fallot (TOF) and pulmonary stenosis (PS) patients referred for pulmonary valve replacement (PVR) have at least moderate tricuspid regurgitation (TR). Predictors of long term TR in this population are not well defined and the role of Tricuspid Annuloplasty (TA) in addition to PVR in this setting is controversial.

Purpose

Patients with preoperative severe TR or moderate TR with dilated tricuspid annulus (&gt;40mm) undergo TA at the time of PVR as per protocol in our instititution. The aim of this observational study was to evaluate the long term results of this approach and to identify predictors of significant TR at the end of follow-up.

Material and methods

We retrospectively reviewed 35 repaired TOF and PS patients who underwent surgical PVR with (n=17, group 1) or without (n=18, group 2) TA in a single tertiary hospital between June-2009 and June-2021. Pre- and postoperative echocardiographic and cardiac magnetic resonance data were assessed for TR severity and right ventricle size and systolic function. Baseline and clinical follow up data were collected. Uni- and multivariable tests were used to analyze predictors of at least moderate TR after PVR.

Results

Mean age at PVR and baseline image parameters were comparable between groups, except for TR grade (p 0.006), tricuspid annulus size (p 0.018) and right ventricle outflow tract diameter (p 0.04) which were greater in group 1. TA did not confer and increased risk of surgical and peroperative complications. Intensive care unit (p 0.94) and total hospital admission days (p 0.59) did not differ among groups. At one year, TR grade significantly improved regardless of TA. At the end of follow-up (5.29±2.9 years), the degree of TR increased in both groups with no differences between groups (p 0.38) (see table 1). In univariable analysis, two independent predictors of at least moderate TR at end of follow-up were identified; mixed TR mechanism (OR 12.5, p 0.006) and severe preoperative TR grade (OR 10.21, p 0.003). Mixed TR mechanism (OR 15.78, p 0.01) and a right ventricle ejection fraction below 45% (OR 1.47, p 0.01) were identified as risk factors of significant TR in multivariable analysis (see Table 2).

Conclusions

TA seems a reasonable approach at the time of PVR in patients with severe TR or moderate TR with dilated annulus. Mixed TR mechanism and a worse right ventricular function have been identified as independent predictors factors of long term significant postoperative TR in our study cohort.

Funding Acknowledgement

Type of funding sources: None.

A study of dose indicators during intra-arterial catheter implantation for liver chemotherapy

The aim of the present study was to describe patient dose indicator levels during intra-arterial catheter (IAC) implantation for liver chemotherapy, and to determine factors affecting the dose indicators. Between January 2017 and January 2019, 61 patients with hepatic metastases from colorectal cancer were retrospectively included. Interventions were carried out in a standardised manner by three experienced radiologists on the same angiographic table without changes in protocol parameters. For each patient, clinical, radiological and dosimetry data were collected, including the air kerma area product (KAP), part of KAP due to the fluoroscopy and fluoroscopy time (FT), total kerma at the reference interventional point and peak skin dose (PSD). Local dose reference levels (RLs) were determined as the third quartile of the patient dose distributions. Univariate and multivariate analysis of factors affecting dose indicators was performed. The mean KAP was 111 Gy cm², the mean reference point air kerma (Ka,r) was 648 mGy, the mean PSD was 613 mGy, and the mean FT was 3190 s (62% of the KAP). The mean cone beam computed tomography dose was 37.3 ± 11.8 Gy cm², which accounted for 37% of the KAP. The RL could be proposed taking into account the third quartiles (KAP = 164.6 Gy cm², Ka,r = 904.5 mGy, FT = 4011 s and standard deviation = 772.7 mGy). The factors affecting dose indicators were related to the patients (sex, cardiovascular risk factors, weight, body mass index), to the vascular anatomies (coeliac trunk angulation) and to the procedures (number of embolised arteries). This study allowed a better understanding of dose indicators and factors affecting these indicators during the implantation of IACs for hepatic chemotherapy, which is a long and difficult procedure. Local dose RLs were determined. Multicentre, multi-equipment studies are necessary.

Utility of a Suture-Mediated Closure System for Large Bore Arterial Access During Challenging Liver Intra-Arterial Catheters Implantation

PURPOSE

To describe and study the utility of vascular suture-mediated closure systems for large bore arterial access during challenging implantation of liver intra-arterial catheters taking as a reference the conventional procedure involving patients without challenging anatomy.

MATERIALS AND METHODS

Between January 2017 and January 2019, 61 consecutive patients underwent 65 intra-arterial catheter IAC implantations for colorectal cancer. Twenty-three procedures (35%) considered by the operators with challenging coeliac trunk angulations were treated using a vascular suture technique where a 6-F introducer was used, the other patients were treated with a conventional 4F access technique. Clinical and radiological characteristics of patients, technical success (implantation of catheters allowing safe infusion of chemotherapy) and complications (Common Terminology Criteria for Adverse Events, CTCAE 5.0) were recorded.

RESULTS

Mean coeliac trunk angulations were 36.3° (± 14.3) for the vascular closure group and 49.6° (± 17.1) for the conventional group. Technical success of the procedures was 100% for the vascular closure group and 80% in the conventional group (p < .05). Four patients with technical failure in the conventional group had a successful IAC implantation on the second attempt using the vascular closure technique. The use of a suture-mediated closure system for large bore arterial access allowed more frequent positioning of the distal tip into the gastro duodenal artery (GDA) (p = .01). No major complication occurred.

CONCLUSION

The use of a large bore arterial access combined with a suture-mediated closure system may be useful for challenging IAC implantation without major complications.

High resolution small-scale inorganic scintillator detector: HDR brachytherapy application

PURPOSE

Brachytherapy (BT) deals with high gradient internal dose irradiation made up of a complex system where the source is placed nearby the tumor to destroy cancerous cells. A primary concern of clinical safety in BT is quality assurance to ensure the best matches between the delivered and prescribed doses targeting small volume tumors and sparing surrounding healthy tissues. Hence, the purpose of this study is to evaluate the performance of a point size inorganic scintillator detector (ISD) in terms of high dose rate brachytherapy (HDR-BT) treatment.

METHODS

A prototype of the dose verification system has been developed based on scintillating dosimetry to measure a high dose rate while using an ¹⁹² Ir BT source. The associated dose rate is measured in photons/s employing a highly sensitive photon counter (design data: 20 photons/s). Dose measurement was performed as a function of source-to-detector distance according to TG43U1 recommendations. Overall measurements were carried out inside water phantoms keeping the ISD along the BT needle; a minimum of 0.1 cm distance was maintained between each measurement point. The planned dwell times were measured accurately from the difference of two adjacent times of transit. The ISD system performances were also evaluated in terms of dose linearity, energy dependency, scintillation stability, signal-to-noise ratio (SNR), and signal-to-background ratio (SBR). Finally, a comparison was presented between the ISD measurements and results obtained from TG43 reference dataset.

RESULTS

The detection efficiency of the ISD was verified by measuring the planned dwell times at different dwell positions. Measurements demonstrated that the ISD has a perfectly linear behavior with dose rate (R²  = 1) and shows high SNR (>35) and SBR (>36) values even at the lowest dose rate investigated at around 10 cm from the source. Standard deviation (1σ) remains within 0.03% of signal magnitude, and less than 0.01% STEM signal was monitored at 0.1 cm source-to-detector distance. Stability of 0.54% is achieved, and afterglow stays less than 1% of the total signal in all the irradiations. Excellent symmetrical behavior of the dose rate regarding source position was observed at different radiation planes. Finally, a comparison with TG-43 reference dataset shows that corrected measurements agreed with simulation data within 1.2% and 1.3%, and valid for the source-to-detector distance greater than 0.25 cm.

CONCLUSION

The proposed ISD in this study anticipated that the system could be promoted to validate with further clinical investigations. It allows an appropriate dose verification with dwell time estimation during source tracking and suitable dose measurement with a high spatial resolution both nearby (high dose gradient) and far (low dose gradient) from the source position.

Safety and benefit of using a virtual bolus during treatment planning for breast cancer treated with arc therapy

Purpose

This study evaluates the benefit of a virtual bolus method for volumetric modulated arc therapy (VMAT) plan optimization to compensate breast modifications that may occur during breast treatment.

Methods

Ten files were replanned with VMAT giving 50 Gy to the breast and 47 Gy to the nodes within 25 fractions. The planning process used a virtual bolus for the first optimization, then the monitors units were reoptimized without bolus, after fixing the segments shapes. Structures and treatment planning were exported on a second scanner (CT) performed during treatment as a consequence to modifications in patient's anatomy. The comparative end‐point was clinical target volume's coverage. The first analysis compared the VMAT plans made using the virtual bolus method (VB‐VMAT) to the plans without using it (NoVB‐VMAT) on the first simulation CT. Then, the same analysis was performed on the second CT. Finally, the level of degradation of target volume coverage between the two CT using VB‐VMAT was compared to results using a standard technique of forward‐planned multisegment technique (Tan‐IMRT).

Results

Using a virtual bolus for VMAT does not degrade dosimetric results on the first CT. No significant result in favor of the NoVB‐VMAT plans was noted. The VB‐VMAT method led to significant better dose distribution on a second CT with modified anatomies compared to NoVB‐VMAT. The clinical target volume's coverage by 95% (V95%) of the prescribed dose was 98.9% [96.1–99.6] on the second CT for VB‐VMAT compared to 92.6% [85.2–97.7] for NoVB‐VMAT (P = 0.0002). The degradation of the target volume coverage for VB‐VMAT is not worse than for Tan‐IMRT: the median differential of V95% between the two CT was 0.9% for VMAT and 0.7% for Tan‐IMRT (P = 1).

Conclusion

This study confirms the safety and benefit of using a virtual bolus during the VMAT planning process to compensate potential breast shape modifications.

Subretinal fibrosis is associated with fundus pulverulentus in pseudoxanthoma elasticum

BACKGROUND

Pseudoxanthoma elasticum (PXE) is a rare autosomal recessive disorder caused by mutations in the ABCC6 gene, resulting in various retinal lesions, among other systemic manifestations. Visual loss may occur in PXE, most commonly caused by choroidal neovascularization and macular atrophy, but little is known about the consequences of fundus pulverulentus (FP) in PXE. The aim of this study was to evaluate ophthalmic outcomes in patients with FP associated with PXE in a large series of PXE patients.

METHODS

In a retrospective observational study, ophthalmic outcomes were compared between two groups of age-matched patients with genetically and pathologically confirmed PXE: one group with FP versus one without FP. All included patients underwent thorough clinical examination. Further investigation (optical coherence tomography (OCT), Cirrhus, Zeiss Germany, and/or fluorescein/indocyanin green angiography) was performed in cases of suspected choroidal neovascularization (CNV).

RESULTS

The study included 13 PXE patients with FP (group 1: 8 men and 5 women, aged 45-65 years) and 47 age-matched PXE patients without FP (group 2: 19 men and 28 women). Mean patient follow-up was 63 months (range 0-132 months). Subretinal fibrosis (SRF) was more frequently associated with FP (9/26 eyes, 34.6%), compared to absence of FP (4/94, 4.2%) (p = 0.0001). Independently of SRF, FP can evolve into deep macular atrophy and/or CNV with dramatic consequences for central vision.

CONCLUSIONS

Fundus pulverulentus may occur in PXE and is most commonly associated with subretinal fibrosis in the posterior pole and visual loss by macular atrophy even in the absence of CNV.

[Hereditary optic atrophies]

INTRODUCTION

Hereditary optic neuropathies, resulting from retinal ganglion cell degeneration, are a heterogeneous group of diseases ranging from asymptomatic forms to legal blindness.

STATE OF KNOWLEDGE

Two most frequent phenotypes are Kjer's disease, an autosomal dominant optic atrophy caused by OPA1 gene mutations, and Leber's disease due to maternally inherited mitochondrial DNA mutations.

PROSPECTS AND CONCLUSION

Both optic neuropathies usually isolated are sometimes associated with extraocular symptoms, especially neurological symptoms, thus justifying a systematic neurological evaluation and brain imaging.

Café-au-lait spots and early onset colorectal neoplasia: a variant of HNPCC?

BACKGROUND

Café-au-lait spots (CALS) are classically found in neurocutaneous syndromes such as neurofibromatosis, but have not been associated with hereditary colorectal cancer. However, review of hereditary colorectal cancer case reports reveals occasional description of CALS on physical exam.

METHODS

We describe the colonic and extracolonic phenotype in a family with CALS and early onset colorectal neoplasia (adenomas and/or cancer) and review 23 additional families reported in the literature.

RESULTS

Among the 24 families, 32/59 (54.2%) individuals had colorectal adenomas diagnosed at a mean age of 15.7 +/- 1.1 (SE) years (range 5-38 years). The majority (24/32, 75.0%) of persons at first colorectal examination had oligopolyposis (< 100 polyps) versus polyposis (> or = 100 polyps). Forty-two of 59 (71.2%) individuals were affected with colorectal cancer, diagnosed at a mean age of 31.9 +/- 2.7 years (range 5-70 years). A brain tumor was found in 28/59 (47.5%) affected individuals (4 families with 2 or more cases) with an overall mean age of diagnosis of 16.5 +/- 1.2. Lymphoma and/or leukemia was found in 8/24 (33.3%) families (one family with 3 cases). Two families had mutation of the mismatch repair gene, hPMS2 (1 with homozygous germline mutation), while two carried homozygous germline mutations of another mismatch repair gene, hMLH1.

CONCLUSIONS

Café-au-lait spots with early onset colorectal neoplasia may identify families with a variant of HNPCC characterized by oligopolyposis, glioblastoma at young age, and lymphoma. This variant may be caused by homozygous mutation of the mismatch repair genes, such as hPMS2 or hMLH1.

Automatic regulation of the cuff pressure in endotracheally-intubated patients

To avoid tracheal wall damage or inadvertent falls of the endotracheal tube cuff pressure (Pcuff) in intubated and mechanically-ventilated patients, the authors devised a simple procedure for automatic and continuous regulation of Pcuff. The procedure, only requiring a simple aquarium air pump and conventional tubing, was first tested at the bench when applied to an intubated and ventilated lung model, including an artificial trachea with an externally-variable section. The clinical performance of the procedure was tested in eight intubated patients, in whom the endotracheal tube cuff was connected to the designed Pcuff regulator during 24 h. The bench test showed that the procedure was able to maintain Pcuff constant, regardless of the changes imposed in the tracheal section. It was also effective in maintaining Pcuff during routine mechanical ventilation. Actual Pcuff recorded over the 24-h period always coincided with the target value within +/-2 cmH2O in all the patients. The procedure devised to maintain endotracheal tube cuff pressure is readily implemented, cheap, easy to operate and can be used regardless of the specific ventilator or tube used. Routine implementation of this procedure may be useful for protecting the trachea from tissue damage and for reducing the risk of ventilator-associated pneumonia.

Electrophysiological effects of corticosteroids on the retinal pigment epithelium

PURPOSE

As corticosteroids appear to intervene in pathogenesis of central serous chorioretinopathy, ion transport changes within the retinal pigment epithelium (RPE) might be involved. Electrophysiological responses to corticosteroid administration were recorded in vivo and in vitro.

METHODS

Clinical study: The standing ocular potential was recorded during intravenous (IV) infusion of glucose 5% and glucose 5% + prednisolone 0.2% in 14 patients with relapsing multiple sclerosis. The results were compared with a control group receiving two successive identical glucose 5% infusions. In vitro study: Native tissue explants (RPE + choroid, porcine, and bovine) were placed in a Ussing-type chamber. After baseline determination of the transepithelial potential (PD), short circuit current (I(sc)) and transepithelial resistance (R(t)), the effect of apical hydrocortisone (HC) 10(-4) M was determined.

RESULTS

Clinical study: A significant rise of the standing potential was found after glucose infusion (P = 0.005), whereas no change was detected after IV glucose + prednisolone (P = 0.695). In vitro study: In the porcine RPE, the mean baseline PD and I(sc) were significantly reduced (both P: = 0.012) after applying apical 10(-4) HC. R(t) was also significantly reduced (P = 0.01). The same type of response, observed in bovine RPE, was reduced in low chloride/low bicarbonate conditions.

CONCLUSIONS

Corticosteroids modified electrophysiological parameters representing RPE function in vivo. The existence of an RPE-specific effect was confirmed in vitro. Further work is required to link the observed ion transport changes to a reduction of apical, subretinal fluid absorption.

Spinal muscular atrophy variant with congenital fractures

A single report of brothers born to first-cousin parents with a form of acute spinal muscular atrophy (SMA) and congenital fractures suggested that this combination represented a distinct form of autosomal recessive SMA. We describe a boy with hypotonia and congenital fractures whose sural nerve and muscle biopsies were consistent with a form of spinal muscular atrophy. Molecular studies identified no abnormality of the SMN(T) gene on chromosome 5. This case serves to validate the suggestion of a distinct and rare form of spinal muscular atrophy while not excluding possible X-linked inheritance.