Low-Frequency Fatigue in Individuals With Spinal Cord Injury

Abstract

Background/Objective: This study examined magnitude and recovery of low-frequency fatigue (LFF) in the quadriceps after electrically stimulated contractions in spinal cord-injured (SCI) and able-bodied subjects.

Subjects: Nine SCI (ASIA A-C, levels C5-T9, injured 13.6 ± 12.2 years) and 9 sedentary able-bodied subjects completed this study.

Methods: Fatigue was evoked in 1 thigh, and the nonfatigued leg served as a control. The fatigue test for able-bodied subjects lasted 15 minutes. For SCI, stimulation was adjusted so that the relative drop in force was matched to the able-bodied group. Force was assessed at 20 (P20) and 100 Hz (PI 00), and the ratio of P20/P100 was used to evaluate LFF in thighs immediately after, at 10, 20, and 60 minutes, and at 2, 4, 6, and 24 hours after a fatigue test.

Results: The magnitude of LFF (up to 1 hour after fatigue) was not different between able-bodied and patients with SCI. However, recovery of LFF over 24 hours was greater in able-bodied compared with patients with SCI in both the experimental (P < 0.001) and control legs (P < 0.001). The able-bodied group showed a gradual recovery of LFF over time in the experimental leg, whereas the SCI group did not.

Conclusions: These results show that individuals with SCI are more susceptible to LFF than able-bodied subjects. In SCI, simply assessing LFF produced considerable LFF and accounted for a substantial portion of the response. We propose that muscle injury is causing the dramatic LFF in SCI, and future studies are needed to test whether “fatigue” in SCI is actually confounded by the effects of muscle injury.     

Impact of trainee involvement with robotic-assisted radical prostatectomy

Robotic-assisted surgery has been rapidly adopted within urology practice. As a result, academic centers are challenged with the burden of how to effectively train residents and fellows to perform robotic-assisted surgery without compromising outcomes. We evaluated the perioperative outcomes of trainee involvement with robotic-assisted radical prostatectomy (RARP) within our healthcare organization. We retrospectively reviewed RARP cases performed at our institution between September 2008 and December 2010 using a single da Vinci robotic platform. Trainees consisted of urology residents and fellows who operated with staff surgeons on select operating days, whereas two staff surgeon teams performed RARP on alternate days. We compared clinicopathologic variables including operating time, estimated blood loss, surgical margin rates, and complication rates between the trainee and staff-only surgeon groups. Overall, 1,019 RARP surgeries were performed within the study period and trainees participated in 162 cases (16 %). Clinical characteristics were similar between men undergoing surgery with a trainee and those without. Positive surgical margin rates were lower for patients with pT2 disease for cases with trainee involvement (11 vs. 19 %, p = 0.02), although overall margin rates and margin rates for patients with pT3 disease were similar between the groups (p = 0.34). Surgical cases involving trainees were longer (241 vs. 200 min, p < 0.001) and resulted in higher estimated blood loss (190 vs. 120 mL, p < 0.001) than the two staff surgeon cases. However, transfusion rates as well as intraoperative and postoperative complication rates did not differ significantly between groups. In conclusion, surgical margin rates were lower in teaching cases for patients with pT2 disease. Importantly, trainee involvement in RARP is safe, with similar perioperative outcomes to staff-only surgical cases. This information may be useful for training and surgical planning.     

Asymptomatic Petechial Eruption on the Lower Legs

The authors report an unusual case of Rocky Mountain spotted fever that presented as an asymptomatic petechial eruption on the lower legs. Rocky Mountain spotted fever is rare in New England and, as such, is typically not on the differential diagnosis when presented with such patients. What began as an asymptomatic eruption progressed to more classic signs of the disease, including a positive Rocky Mountain spotted fever titer. The patient was successfully treated with doxycydine and within a short period of time, was completely back at baseline.A 70-year-old woman from Massachusetts presented with a two-day history of an asymptomatic petechial eruption on the ankles and distal shins. She was in excellent health and denied daily medications. There were no associated systemic symptoms and she denied any recent travel except for a recent vacation to Vermont. She denied any recent arthropod bites or new environmental exposures.Examination revealed numerous small 2 to 3mm palpable petechiae solely on the distal lower extremities, ankles, and feet (Figure 1). Physical examination findings were otherwise unremarkable; no lymphadenopathy was seen and a thorough review of systems was unremarkable. Open in a separate windowFigure 1Clinical photo of Rocky Mountain spotted fever demonstrating characteristic petechial eruptionA punch biopsy specimen was taken for histologic examination (Figure 2). The histopathologic examination of the biopsy specimen revealed superficial and deep perivascular inflammation with numerous extravasated erythrocytes without evidence of vasculitis. This was deemed to be most consistent with a purpuric generalized cutaneous hypersensitivity reaction. Results from a complete blood count, erythrocyte sedimentation rate, extensive chemistry panel, and liver function tests revealed normal findings. Cerebrospinal fluid analysis revealed elevated protein at 60.8mg/dL (normal=15—45mg/dL), but was otherwise unremarkable. Lyme immunoglobulins were undetectable (<lU/mL), and anti-nuclear and P and C antineutrophil cytoplasmic antibody titers were negative (<1:20). However, the patient’s Rocky Mountain spotted fever (RMSF) immunoglobulin G titer was positive and a diagnosis of RMSF was made. Open in a separate windowFigure 2Histopathology photo (10x) of Rocky Mountain spotted fever demonstrating superficial and deep perivascular lymphocytic infiltration with extravasated erythrocytesThe patient, initially asymptomatic, presented with severe headache and spiking fevers, prompting an inpatient workup. She was started on empiric doxycycline, which was continued for 14 days after her RMSF titer returned positive. Within three days, her fevers and headache subsided and by one week, her petechial eruption virtually disappeared.     

Association study of the vesicular monoamine transporter gene SLC18A2 with tardive dyskinesia

Tardive dyskinesia (TD) is an involuntary movement disorder that can occur in up to 25% of patients receiving long-term first-generation antipsychotic treatment. Its etiology is unclear, but family studies suggest that genetic factors play an important role in contributing to risk for TD. The vesicular monoamine transporter 2 (VMAT2) is an interesting candidate for genetic studies of TD because it regulates the release of neurotransmitters implicated in TD, including dopamine, serotonin, and GABA. VMAT2 is also a target of tetrabenazine, a drug used in the treatment of hyperkinetic movement disorders, including TD. We examined nine single-nucleotide polymorphisms (SNPs) in the SLC18A2 gene that encodes VMAT2 for association with TD in our sample of chronic schizophrenia patients (n = 217). We found a number of SNPs to be nominally associated with TD occurrence and the Abnormal Involuntary Movement Scale (AIMS), including the rs2015586 marker which was previously found associated with TD in the CATIE sample ( Tsai et al., 2010), as well as the rs363224 marker, with the low-expression AA genotype appearing to be protective against TD (p = 0.005). We further found the rs363224 marker to interact with the putative functional D2 receptor rs6277 (C957T) polymorphism (p = 0.001), supporting the dopamine hypothesis of TD. Pending further replication, VMAT2 may be considered a therapeutic target for the treatment and/or prevention of TD.     

Argyrophilic grain disease differs from other tauopathies by lacking tau acetylation

Post-translational modifications play a key role in tau protein aggregation and related neurodegeneration. Because hyperphosphorylation alone does not necessarily cause tau aggregation, other post-translational modifications have been recently explored. Tau acetylation promotes aggregation and inhibits tau’s ability to stabilize microtubules. Recent studies have shown co-localization of acetylated and phosphorylated tau in AD and some 4R tauopathies. We developed a novel monoclonal antibody against acetylated tau at lysine residue 274, which recognizes both 3R and 4R tau, and used immunohistochemistry and immunofluorescence to probe 22 cases, including AD and another eight familial or sporadic tauopathies. Acetylated tau was identified in all tauopathies except argyrophilic grain disease (AGD). AGD is an age-associated, common but atypical 4R tauopathy, not always associated with clinical progression. Pathologically, AGD is characterized by neuropil grains, pre-neurofibrillary tangles, and oligodendroglial coiled bodies, all recognized by phospho-tau antibodies. The lack of acetylated tau in these inclusions suggests that AGD represents a distinctive tauopathy. Our data converge with previous findings to raise the hypothesis that AGD could play a protective role against the spread of AD-related tau pathology. Tau acetylation as a key modification for the propagation tau toxicity deserves further investigation.     

International consensus classification of hippocampal sclerosis in temporal lobe epilepsy: A Task Force report from the ILAE Commission on Diagnostic Methods

Hippocampal sclerosis (HS) is the most frequent histopathology encountered in patients with drug‐resistant temporal lobe epilepsy (TLE). Over the past decades, various attempts have been made to classify specific patterns of hippocampal neuronal cell loss and correlate subtypes with postsurgical outcome. However, no international consensus about definitions and terminology has been achieved. A task force reviewed previous classification schemes and proposes a system based on semiquantitative hippocampal cell loss patterns that can be applied in any histopathology laboratory. Interobserver and intraobserver agreement studies reached consensus to classify three types in anatomically well‐preserved hippocampal specimens: HS International League Against Epilepsy (ILAE) type 1 refers always to severe neuronal cell loss and gliosis predominantly in CA1 and CA4 regions, compared to CA1 predominant neuronal cell loss and gliosis (HS ILAE type 2), or CA4 predominant neuronal cell loss and gliosis (HS ILAE type 3). Surgical hippocampus specimens obtained from patients with TLE may also show normal content of neurons with reactive gliosis only (no‐HS). HS ILAE type 1 is more often associated with a history of initial precipitating injuries before age 5 years, with early seizure onset, and favorable postsurgical seizure control. CA1 predominant HS ILAE type 2 and CA4 predominant HS ILAE type 3 have been studied less systematically so far, but some reports point to less favorable outcome, and to differences regarding epilepsy history, including age of seizure onset. The proposed international consensus classification will aid in the characterization of specific clinicopathologic syndromes, and explore variability in imaging and electrophysiology findings, and in postsurgical seizure control.     

Corticosteroids in Duchenne muscular dystrophy: Major variations in practice

Introduction: In 2004, a Cochrane Review and AAN practice parameter concluded that prednisone 0.75 mg/kg/day is of short‐term efficacy in Duchenne muscular dystrophy (DMD). Subsequent efforts to standardize care for DMD indicated wide variation in corticosteroid use. Methods: We surveyed physicians who follow patients with DMD, including: (1) clinics in the TREAT‐NMD (Translational Research in Europe—Assessment and Treatment of Neuromuscular Diseases) network (predominantly Europe) and (2) U.S. MDA clinic directors. We also documented the co‐administered corticosteroids in a trial of a putative treatment (ataluren) for DMD. Results: Of 105 Treat‐NMD clinicians, corticosteroids were not used in 10 clinics, and 29 different regimens were used—the most frequent 0.75 mg/kg/day prednisone (61 centers); 10 days on/10 days off (36 centers); 0.9 mg/kg/day deflazacort (32 centers); and 5 mg/kg/day on weekends (10 centers). Similar diversity was identified in MDA clinics and in the ataluren trial. Conclusions: Variability in corticosteroid use suggests uncertainty about risks/benefits of corticosteroid regimens for DMD. Muscle Nerve, 2013     

Testing single‐ and dual‐route computational models of auditory repetition with new data from six aphasic patients

Background: Deficits in the production of complex structures have been widely documented in non-fluent forms of aphasia. Nevertheless, the data available on fluent deficits are scarcer. In both cases, reduced complexity is attributed to syntactic factors. In the related field of syntactic theory, there exist a number of studies on the production of non-brain damaged (NBD) subjects which try to account for the existence of two alternative constructions in embedded complement clauses in English (as in I think that the situation will improve/I think the situation will improve). The absence of that in the embedded clauses of verbs like say, know or think in colloquial English is very frequent and this suggests that verbs of this type may select a clause lacking a complementiser phrase (CP) layer, namely tense phrase (TP). The presence of that is taken to be the result of insertion, which is triggered by cues associated to contextual factors like register.

Aims: To compare the presence and absence of the complementiser that in the speech of English subjects diagnosed with aphasia with the same phenomenon in NBD subjects with the objective of clarifying the nature of the phenomenon of that-omission.

Methods &; Procedures: We carried out an analysis of spontaneous speech that included the performance of 200 individuals brought together by the AphasiaBank project. Two groups were included in the study, an experimental group comprising 100 individuals diagnosed as aphasic according to the standards of the Western Aphasia Battery (WAB), and a control group including 100 non-brain damaged control subjects ( NBDs).

Outcomes &; Results: This study shows that the asymmetries across populations (NBDs vs. subjects with aphasia) are restricted to the number of occurrences of subordinate clauses. NBD subjects produce more embeddings than subjects diagnosed with fluent aphasia (although they do produce embedded clauses and crucially prefer the “omission” option) and subjects with non-fluent aphasia.

Conclusions: Our results confirm the findings on fluent aphasias as for the presence of deficits with complex constructions. These results may be regarded as evidence for the claim that TP is the default selection for the verbs analysed.     

Connectionist diagnosis of lexical disorders in aphasia

Background: In the cognitive neurolinguistic approach to lexical deficits in aphasia, impaired levels of processing are localised in a cognitive model. Model-oriented treatment may target these impaired components. Thus a precise assessment of the disorder is crucial. Connectionist models add to this by using computer simulation to specify the details of the functioning of these components. The connectionist semantic-phonological model of lexical access (Dell, Martin, & Schwartz, 2007 Dell, G. S., Martin, N. and Schwartz, M. F. 2007. A case-series test of the interactive two-step model of lexical access: Predicting word repetition from picture naming. Journal of Memory and Language, 56: 490–520. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]; Schwartz, Dell, Martin, Gahl, & Sobel, 2006 Schwartz, M. F., Dell, G. S., Martin, N., Gahl, S. and Sobel, P. 2006. A case-series test of the interactive two-step model of lexical access: Evidence from picture naming. Journal of Memory and Language, 54: 223–264.  [Google Scholar]) explores the impairment by simulating error patterns in naming and repetition.

Aims: The purpose of the present study was to investigate the model's range of application as a diagnostic tool, and to derive recommendations for the model's use in clinical settings.

Methods & Procedures: We demonstrate how we adapted the error analysis to 15 German-speaking patients with aphasia, analysed the model's accuracy in assessing naming and repetition disorders, and explained deviations between the error pattern produced by each patient and the one produced by the model's simulation by appealing to an extended version of the model.

Outcomes & Results: Overall, the model yielded good fits of the patients' error patterns. Larger model–patient deviations could be explained by the model's limited set of lesionable components.

Conclusions: The “connectionist diagnosis” of naming and repetition disorders in the semantic-phonological model is a reasonable tool in model-oriented assessment. However, the diagnosis needs to be complemented by further language tests.     

Desmoplastic fibroma of the pediatric cranium: case report and review of the literature

Purpose

Desmoplastic fibromas are primary bone tumors that seldom occur in the cranial bones. Furthermore, reports of desmoplastic fibromas of the skull in children are exceedingly rare. Although desmoplastic fibromas are histologically benign, they are locally aggressive and have a propensity to reoccur. Their radiographic appearance may mimic other more common central nervous system and bone neoplasms. There are only 19 reported cases of desmoplastic fibroma of the cranium in the literature, and only seven occurred in the pediatric age group. We present a case report of an 11-year-old female patient with a desmoplastic fibroma of the parieto-occipital region and review the literature.

Case report

An 11-year-old female presented to the craniofacial clinic complaining of intermittent pain and a soft mass in the occipital region. There was a distant history of trauma to the region that did not require medical intervention. Computed tomography imaging revealed a lytic bone lesion overlying the sagittal sinus in the parieto-occipital region. Surgical resection with wide margins and immediate autologous reconstruction was performed. Pathological analysis revealed a desmoplastic fibroma. At 4 months of follow-up, no recurrence has been noted.

Conclusion

Desmoplastic fibroma of the cranium is rare. Complete surgical resection with careful follow-up is the treatment of choice.