Roberto S. Martins

Prognostic factors and treatment of penetrating gunshot wounds to the head

BACKGROUND In an attempt to evaluate the predictive factors of morbidity and mortality in patients who suffered from civilian gunshot wounds to the head, we reviewed a series of 319 patients admitted to the Hospital Santa Marcelina, São Paulo, Brazil, between 1994 and 2000. METHODS Clinical and cranial computed tomography (CT) results are described. The initial Glasgow Coma Scale (GCS), the presence of an unilateral dilated pupil or medium fixed pupils, and five different findings in the CT scan were considered as variables. The Qui-Square Fisher test was utilized to verify the correlation between the presence of the variables and the occurrence of an increased mortality rate and of an unfavorable outcome (Glasgow Outcome Scale = 2 and 3). RESULTS In 265 cases the missile penetrated the dura (83%). In our study there was a significant correlation between the low GCS scores on admission and a higher mortality (p < 0.001). This kind of correlation was also noted with patients admitted with unilateral dilated pupil and medium fixed pupil. There were 187 patients (70.5%) evaluated by CT scan. There was a significant correlation between the presence of transventricular or bihemispheric central type trajectory and high mortality. The patients admitted with unilobar supratentorial wounds resulted in better outcome when compared to those with bilobar or multilobar wounds (p < 0.001). A group of 156 patients was submitted to an aggressive surgical protocol. The best results were seen in patients admitted with initial GCS score higher than 8. CONCLUSIONS We conclude that low GCS scores at admission, unilateral dilated pupil or medium fixed pupil, transventricular or bihemispheric central type trajectory, and bilobar or multilobar wounds noted through CT scan are predictive factors of high morbidity and mortality in patients with gunshot wounds to the head, in our clinical experience. We also conclude that surgical treatment is not recommended for patients with penetrating wounds and GCS score of 3 to 5 in the absence of hematoma causing a mass effect.

Early motor and electrophysiological changes in transgenic mouse model of amyotrophic lateral sclerosis and gender differences on clinical outcome

Amyotrophic lateral sclerosis (ALS) is a progressive degenerative disorder affecting motoneurons and the SOD1(G93A) transgenic mice are widely employed to study disease physiopathology and therapeutic strategies. Despite the cellular and biochemical evidences of an early motor system dysfunction, the conventional behavioral tests do not detect early motor impairments in SOD1 mouse model. We evaluated early changes in motor behavior of ALS mice by doing the analyses of tail elevation, footprint, automatic recording of motor activities by means of an infrared motion sensor activity system and electrophysiological measurements in male and female wild-type (WT) and SOD1(G93A) mice from postnatal day (P) 20 up to endpoint. The classical evaluations of mortality, weight loss, tremor, rotometer, hanging wire and inclined plane were also employed. There was a late onset (after P90) of the impairments of classical parameters and the outcome varied between genders of ALS mice, being tremor, cumulative survival, weight loss and neurological score about 10 days earlier in male than female ALS mice and also about 20 days earlier in ALS males regarding rotarod and hanging wire performances. While diminution of hindpaw base was 10 days earlier in ALS males (P110) compared to females, the steep length decreased 40 days earlier in ALS females (P60) than ALS males. The automatic analysis of motor impairments showed substantial late changes (after P90) of motility and locomotion in the ALS females, but not in the ALS males. It was surprising that the scores of tail elevation were already decreased in ALS males and females by P40, reaching the minimal values at the endpoint. The electrophysiological analyses showed early changes of measures in the ALS mouse sciatic nerve, i.e., decreased values of amplitude (P40) and nerve conduction velocity (P20), and also an increased latency (P20) reaching maximal level of impairments at the late disease phase. The early changes were not accompanied by reductions of neuronal protein markers of neurofilament 200 and ChAT in the ventral part of the lumbar spinal cord of P20 and P60 ALS mice by means of Western blot technique, despite remarkable decreases of those protein levels in P120 ALS mice. In conclusion, early changes of motor behavior and electrophysiological parameters in ALS mouse model must be taken into attention in the analyses of disease mechanisms and therapeutic effects.

Phrenic nerve transfer in the restoration of elbow flexion in brachial plexus avulsion injuries: how effective and safe is it?

OBJECTIVE Phrenic nerve transfer has been used for treating lesions of the brachial plexus since 1970. Although, today, surgeons are more experienced with the technique, there are still widespread concerns about its effects on pulmonary function. This study was undertaken to evaluate the effectiveness and safety of this procedure. METHODS Fourteen patients with complete palsy of the upper limb were submitted to phrenic nerve transfer as part of a strategy for surgical reconstruction of their plexuses. Two patients were lost to follow-up, and 2 patients were followed for less than 2 years. Of the remaining 10 patients, 9 (90%) were male. The lesions affected both sides equally. The mean age of the patients was 24.8 years (range, 14-43 years), and the mean interval from injury to surgery was 6 months (range, 3-9 months). The phrenic nerve was always transferred to the musculocutaneous nerve, and a nerve graft (mean length, 8 cm; range, 4.5-12 cm) was necessary in all cases. RESULTS There was no major complication related to the surgery. Seven patients (70%) recovered functional level biceps strength (Medical Research Council grade >or=3). All of the patients exhibited a transient decrease in pulmonary function tests, but without clinical respiratory problems. CONCLUSION On the basis of our small series and data from the literature, we conclude that phrenic nerve transfer in well-selected patients is a safe and effective procedure for recovering biceps function.OBJECTIVEPhrenic nerve transfer has been used for treating lesions of the brachial plexus since 1970. Although, today, surgeons are more experienced with the technique, there are still widespread concerns about its effects on pulmonary function. This study was undertaken to evaluate the effectiveness and safety of this procedure. METHODSFourteen patients with complete palsy of the upper limb were submitted to phrenic nerve transfer as part of a strategy for surgical reconstruction of their plexuses. Two patients were lost to follow-up, and 2 patients were followed for less than 2 years. Of the remaining 10 patients, 9 (90%) were male. The lesions affected both sides equally. The mean age of the patients was 24.8 years (range, 14–43 years), and the mean interval from injury to surgery was 6 months (range, 3–9 months). The phrenic nerve was always transferred to the musculocutaneous nerve, and a nerve graft (mean length, 8 cm; range, 4.5–12 cm) was necessary in all cases. RESULTSThere was no major complication related to the surgery. Seven patients (70%) recovered functional level biceps strength (Medical Research Council grade ≥3). All of the patients exhibited a transient decrease in pulmonary function tests, but without clinical respiratory problems. CONCLUSIONOn the basis of our small series and data from the literature, we conclude that phrenic nerve transfer in well-selected patients is a safe and effective procedure for recovering biceps function.

Magnetic resonance imaging of idiopathic carpal tunnel syndrome: Correlation with clinical findings and electrophysiological investigation

OBJECTIVE To compare clinical evaluation, electrophysiological investigation and magnetic resonance findings in assessing the severity of idiopathic carpal tunnel syndrome. PATIENTS AND METHODS Seventy-four patients with idiopathic carpal tunnel syndrome were prospectively recruited. Clinical evaluation included symptoms severity score and two-point discrimination, sensory and motor nerve conduction velocities were determined by electroneuromyography and imaging parameters were obtained after wrist magnetic resonance. The Wilcoxon test was used to define the differences between measurements of median nerve area. The Pearson and Spearman correlation tests were used to determine the relationships between all the measured parameters. RESULTS Cross-sectional area of median nerve was smaller at hamate level than at radio-ulnar joint and pisiform levels (p<0.001). With exception of median nerve area at hamate level, there was a lower degree of correlation between MRI parameters and findings obtained by clinical assessments and electrophysiological measurements. The median nerve area at hamate level correlated negatively with duration of symptoms, two-point discrimination, symptoms severity score and positively with sensory nerve conduction velocity (p<0.01). CONCLUSION In patients with idiopathic carpal tunnel syndrome, median nerve area measured by wrist magnetic resonance at hamate level may be considered as a valuable indicator to grading the severity of disease.

Correlation between parameters of electrophysiological, histomorphometric and sciatic functional index evaluations after rat sciatic nerve repair

The rat sciatic nerve is a well-established model for the study of recovery from peripheral nerve injuries. Traditional methods of assessing nerve regeneration after nerve injury and repair, such as electrophysiology and histomorphometry, despite widely used in neural regeneration experiments, do not necessarily correlate with return of motor and sensory functions. The aim of this experimental study is to investigate the possible correlation between several parameters of peripheral nerve regeneration after repair of sectioned sciatic nerve in Wistar rat. A two-stage approach was used to obtain 17 parameters after electrophysiological, morphometric and sciatic functional index evaluations. Pearsons correlation analysis was performed between these results. Only two positives correlations between different classes of peripheral nerve assessments were noted, between sciatic functional index and proximal nerve fiber diameter (r=0.56, p<0.01) and between sciatic functional index and distal fiber diameter (r=0.50, p<0.01). The data presented in our study demonstrates that there is a poor correlation between the sciatic functional index and outcome measures of electrophysiological and morphometric evaluations.

Surgical management of Guyon's canal syndrome, an ulnar nerve entrapment at the wrist: report of two cases

Guyons canal syndrome, an ulnar nerve entrapment at the wrist, is a well-recognized entity. The most common causes that involve the ulnar nerve at the wrist are compression from a ganglion, occupational traumatic neuritis, a musculotendinous arch and disease of the ulnar artery. We describe two cases of Guyons canal syndrome and discuss the anatomy, aetiology, clinical features, anatomical classification, diagnostic criteria and treatment. It is emphasized that the knowledge of both the surgical technique and anatomy is very important for a satisfactory surgical result.

Hemihypoglossal-facial neurorrhaphy after mastoid dissection of the facial nerve: results in 24 patients and comparison with the classic technique.

OBJECTIVEHypoglossal–facial neurorrhaphy has been widely used for reanimation of paralyzed facial muscles after irreversible proximal injury of the facial nerve. However, complete section of the hypoglossal nerve occasionally results in hemiglossal dysfunction and interferes with swallowing and speech. To reduce this morbidity, a modified technique with partial section of the hypoglossal nerve after mastoid dissection of the facial nerve (HFM) has been used. We report our experience with the HFM technique, retrospectively comparing the outcome with results of the classic hypoglossal-facial neurorrhaphy. METHODSA retrospective review was performed in 36 patients who underwent hypoglossal-facial neurorrhaphy with the classic (n = 12) or variant technique (n = 24) between 2000 and 2006. Facial outcome was evaluated with the House-Brackmann grading system, and tongue function was evaluated with a new scale proposed to quantify postoperative tongue alteration. The results were compared, and age and time between nerve injury and surgery were correlated with the outcome. RESULTSThere was no significant difference between the two techniques concerning facial reanimation. A worse outcome of tongue function, however, was associated with the classic technique (Mann-Whitney U test; P < 0.05). When HFM was used, significant correlations defined by the Spearman test were identified between preoperative delay (ρ = 0.59; P = 0.002) or age (ρ = 0.42; P = 0.031) and results of facial reanimation evaluated with the House-Brackmann grading system. CONCLUSIONHFM is as effective as classic hypoglossal-facial neurorrhaphy for facial reanimation, and it has a much lower morbidity related to tongue function. Better results are obtained in younger patients and with a shorter interval between facial nerve injury and surgery.

Electrophysiologic assessment of regeneration in rat sciatic nerve repair using suture, fibrin glue or a combination of both techniques

We evaluated the repair of sectioned rat sciatic nerve by the comparison of electrophysiologic parameters. The repair was effected with suture (group A), fibrin glue (group B) or a combination of both techniques (group C). The amplitude, latency and conduction velocity of the motor and nerve action potentials were assessed before the nerve section and at reoperation after 24 weeks. There was no difference between the groups when the nerve action potential was evaluated. Rats of group B presented better results than those of group A (p<0.05) when latency and the nerve conduction velocity assessed at the reoperation, and the ratio between the conduction velocity at the reoperation and before the nerve section in the motor action potential evaluation were measured. Animals of group C presented better results than those of group A when the ratio between the conduction velocity of motor action potential at the reoperation and before the nerve division was considered (p<0.05). No difference between groups B and C was found. We conclude that repair using fibrin glue presented better results than suture following transection of sciatic nerve when the motor action potential was evaluated in the rat experimental model.

Efficacy and safety of Oberlin's procedure in the treatment of brachial plexus birth palsy.

BACKGROUND In brachial plexus injuries, when there are no available roots to use as a source for graft reconstruction, nerve transfers emerge as an elective technique. For this purpose, transfer of an ulnar nerve fascicle to the biceps motor branch (Oberlins procedure) is often used. Despite the high rate of good to excellent results in adults, this technique is seldom used in children. OBJECTIVE To evaluate the efficacy and safety of Oberlins procedure in the surgical treatment of brachial plexus birth palsy. METHODS Striving to restore elbow flexion, we performed Oberlins procedure in 17 infants with brachial plexus birth palsy. After follow-up of at least 19 months, primary outcomes were the strength of elbow flexion (modified British Medical Research Council scale), hand function measured using Al-Qattans scale, and comparative x-rays of both hands to detect altered growth. RESULTS Good to excellent results related to biceps contraction were obtained in 14 patients (82.3%) (3/MRC3, 11/MRC4). The preoperative Al-Qattan scale score for the hand was maintained at final follow-up. Comparing the treated and normal limb, no difference was observed in hand development by x-ray. CONCLUSION Oberlins procedure is an effective and safe option for the surgical treatment of upper brachial plexus birth palsy.

Gene expression profiling for human iPS-derived motor neurons from sporadic ALS patients reveals a strong association between mitochondrial functions and neurodegeneration

Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease that leads to widespread motor neuron death, general palsy and respiratory failure. The most prevalent sporadic ALS form is not genetically inherited. Attempts to translate therapeutic strategies have failed because the described mechanisms of disease are based on animal models carrying specific gene mutations and thus do not address sporadic ALS. In order to achieve a better approach to study the human disease, human induced pluripotent stem cell (hiPSC)-differentiated motor neurons were obtained from motor nerve fibroblasts of sporadic ALS and non-ALS subjects using the STEMCCA Cre-Excisable Constitutive Polycistronic Lentivirus system and submitted to microarray analyses using a whole human genome platform. DAVID analyses of differentially expressed genes identified molecular function and biological process-related genes through Gene Ontology. REVIGO highlighted the related functions mRNA and DNA binding, GTP binding, transcription (co)-repressor activity, lipoprotein receptor binding, synapse organization, intracellular transport, mitotic cell cycle and cell death. KEGG showed pathways associated with Parkinsons disease and oxidative phosphorylation, highlighting iron homeostasis, neurotrophic functions, endosomal trafficking and ERK signaling. The analysis of most dysregulated genes and those representative of the majority of categorized genes indicates a strong association between mitochondrial function and cellular processes possibly related to motor neuron degeneration. In conclusion, iPSC-derived motor neurons from motor nerve fibroblasts of sporadic ALS patients may recapitulate key mechanisms of neurodegeneration and may offer an opportunity for translational investigation of sporadic ALS. Large gene profiling of differentiated motor neurons from sporadic ALS patients highlights mitochondrial participation in the establishment of autonomous mechanisms associated with sporadic ALS.