Ricardo B. V. Fontes

Acute Neurogenic Pulmonary Edema: Case Reports and Literature Review

Neurogenic pulmonary edema (NPE) is an underdiagnosed clinical entity. Its pathophysiology is multifactorial but largely unknown. We report two cases of NPE and review the literature on NPE cases reported since 1990. A 21-year-old man had a seizure episode following cranioplasty. He became increasingly dyspneic, and clinical and laboratory signs of respiratory failure were evident. Chest radiography and computed tomography showed bilateral diffuse infiltrates. After supportive measures were taken, complete respiratory recovery occurred in 72 hours. A 52-year-old woman had several seizure episodes following subarachnoid hemorrhage due to a cavernoma. She became increasingly dyspneic upon arrival at the hospital. After tracheostomy and oxygen support were established, chest radiography showed bilateral diffuse infiltrates. Respiratory recovery was excellent, and the patient was eupneic with normal results of chest radiography 48 hours later. Fourteen reports (21 cases) were found. Thirteen patients were female, and the mean age of the patients was 31.6 years. The most frequent underlying factor was subarachnoid hemorrhage (42.9%). Symptom onset occurred <4 hours after the neurologic event in 71.4% of cases. One third of the patients presented with pink frothy sputum. Chest radiography showed bilateral diffuse infiltrates in 90.5% of cases. Supportive measures included oxygen support and vasoactive drugs. Recovery was usually very rapid: 52.4% of patients recovered in <72 hours. Almost 10% of patients died of NPE. Our two cases had clinical and laboratory features in common with most NPE cases. Physicians should remember NPE when neurologic patients suddenly become dyspneic. The mortality rate is high, but surviving patients usually recover very quickly.

Anatomic Study of the Filum Terminale and Its Correlations with the Tethered Cord Syndrome

OBJECTIVE To evaluate the intradural anatomic features of the filum terminale (FT) in fresh human cadavers, analyzing morphological parameters relevant for the diagnosis of the tethered cord syndrome. METHODS Forty-one fresh cadavers were dissected, and the following parameters were evaluated: cadaver height, weight, and age, FT length, FT diameters at the initial point and midpoint, and topographic relationships of the initial and fusion points of the FT to the adjacent vertebrae. RESULTS The mean FT length was 156.44 mm (range, 112.8–211.1 mm), the mean initial diameter was 1.38 mm (range, 0.4–2.5 mm), and the mean midpoint diameter was 0.76 mm (range, 0.1–1.55 mm). Four specimens (9.76%) exhibited FT thicknesses of more than 2 mm at their initial points. The FT most frequently started at the middle L1 level (19.51%) and fused with the dura mater at the upper S2 level (31.71%). Two fila (4.88%) started below the L2 level. Statistically significant correlations were observed (Pearson correlation, P < 0.05) between specimen weight and height (P = 0.019), initial point and midpoint diameters of the FT (P < 0.001), initial vertebral level and specimen height (P = 0.012), and initial and fusion vertebral levels (P = 0.004). CONCLUSION Variation ranges were large for almost all anatomic parameters of the FT. Six cadavers (14.63%) in our study fulfilled one of the anatomic diagnostic criteria for tethered cord syndrome. Neurosurgeons must remember the normal variations in the anatomic features of this region when establishing the diagnosis of tethered cord syndrome or performing surgical procedures involving the caudal part of the dural sac.

Ultrastructural study of the filum terminale and its elastic fibers.

OBJECTIVE:The filum terminale (FT) is a fibrovascular band involved in the pathophysiology of tethered cord syndrome (TCS). Its morphological and ultrastructural properties remain largely unknown even though they are thought to play a role in the generation of TCS in adult patients with normal level conus medullaris. MATERIALS AND METHODS:Twenty fresh adult human cadavers had their fila measured and removed. Transversal and longitudinal sections of the proximal, middle, and distal thirds of FT were submitted to light microscopy analysis with four different techniques. Five fila were selected for longitudinal and transversal scanning electron microscopy analysis. RESULTS:The bulk of the FT is composed of 5- to 20-&mgr;m thick longitudinal bundles of Type 1 collagen separated by 3- to 10-&mgr;m intervals, although capillaries and other elements may be present. A delicate (0.05–1.5 &mgr;m) meshwork of predominantly Type 3 collagen transversal fibers connects these bundles. Abundant longitudinally oriented elastic and elaunin fibers are found inside collagen bundles. A complex tridimensional structure is evidenced on electron microscopy. CONCLUSION:The longitudinal arrangement of collagen bundles and the impressive amount of elastic and elaunin fibers should elicit considerable elastic properties to the FT. An altered elasticity mechanism has been proposed for TCS; further studies are needed with TCS patients to define whether the collagen structure, Type 1/Type 3 proportion, or elastic fiber content are altered, which could lead to new histopathological definitions of TCS, helping neurosurgeons in the difficult management of TCS patients with normal level conus medullaris.

Effects of pre- and postnatal protein deprivation and postnatal refeeding on myenteric neurons of the rat small intestine: A quantitative morphological study

We investigated weight gain, the size of the small intestine and numbers and sizes of enteric neurons in rats whose mothers had been deprived of protein during pregnancy and who themselves were deprived postpartum. Postnatally, protein deprivation was for 42 days, or for 21 days with refeeding for a further 21 days. Control animals received normal nourishment. Neurons were located by nicotinamide adenine dinucleotide (NADH) diaphorase staining, by acetylcholinesterase (AChE) activity and immunoreactivity for choline acetyltransferase (ChAT). The collagen and elastic fibers in the myenteric ganglia were evaluated histologically. The myenteric ganglia were regular and uniform in the nourished and refed groups. In the undernourished group, the myenteric ganglia were irregularly arranged and the cytoplasm of most of the neurons showed less intense staining for NADH diaphorase, AChE and ChAT. AChE activity and ChAT immunoreactivity showed that most ganglionic neurons were stained in nourished and refed groups, but the neurons of undernourished rats were unstained or moderately stained. The distribution of the connective tissue of the ganglionic capsule was similar in the three groups. There was a decrease in weight of undernourished rats, which was restored in refed rats. The size of the small intestine of the undernourished group was smaller than in the normally fed group, by about 45%, but it was similar in nourished and refed rats. After 42 days of protein deprivation the numbers of neurons that were revealed by NADH diaphorase were fewer than in well nourished rats, but numbers were not different between nourished and refed rats. These observations indicate that protein deprivation alters histological features and acetylcholinesterase activity of neurons and also reduces body weight but these were restored by refeeding.

Massive cerebral involvement in fat embolism syndrome and intracranial pressure management.

Fat embolism syndrome (FES) is a common clinical entity that can occasionally have significant neurological sequelae. The authors report a case of cerebral fat embolism and FES that required surgical management of intracranial pressure (ICP). They also discuss the literature as well as the potential need for neurosurgical management of this disease entity in select patients. A 58-year-old woman presented with a seizure episode and altered mental status after suffering a right femur fracture. Head CT studies demonstrated hypointense areas consistent with fat globules at the gray-white matter junction predominantly in the right hemisphere. This CT finding is unique in the literature, as other reports have not included imaging performed early enough to capture this finding. Brain MR images obtained 3 days later revealed T2-hyperintense areas with restricted diffusion within the same hemisphere, along with midline shift and subfalcine herniation. These findings steered the patient to the operating room for decompressive hemicraniectomy. A review of the literature from 1980 to 2012 disclosed 54 cases in 38 reports concerning cerebral fat embolism and FES. Analysis of all the cases revealed that 98% of the patients presented with mental status changes, whereas only 22% had focal signs and/or seizures. A good outcome was seen in 57.6% of patients with coma and/or abnormal posturing on presentation and in 90.5% of patients presenting with mild mental status changes, focal deficits, or seizure. In the majority of cases ICP was managed conservatively with no surgical intervention. One case featured the use of an ICP monitor, while none featured the use of hemicraniectomy.

Comparative study of the strength of the flexor and extensor muscles of the knee through isokinetic evaluation in normal subjects and patients subjected to trans-tibial amputation

This study compares the strength of the flexor and extensor muscles of the knee in a group (A) of 25 patients with unilateral trans-tibial amputation, regardless of cause, and a group (B) of 27 normal volunteers. Measured parameters were peak bending moment, total work, maximum power and flexor/extensor relation. The dynamometer used was a Cybex® model 6000, set at velocities of 60°/s and 180°/s (4 and 20 repetitions). Exercise type was concentric, both for flexion and extension of the knee joint. Patients were grouped according to stump size, age and time since amputation. These patients were tested with their prosthesis. Mean age in group A was 35.9 ± 13 years (age range: 12–59 years). Mean age in group B was 34 ± 8 years (age range: 19–56 years). Comparison according to subject sex was similar. Data analysis between the amputated and the sound limb reveals strength deficit (bigger deficit at 180°/s), which relates to age but not to stump size. When compared to non-amputated subjects in the measured parameters, negative relations both in the amputated side and the non-amputated side were found. The authors’ conclusion is that revision of the parameters used until then for rehabilitation of the patients subjected to trans-tibial amputation is needed.

Angiographic Evaluation of Graft Patency in Minimally Invasive Direct Coronary Artery Bypass Grafting

BACKGROUND The objective of this report is to describe our experience using minimally invasive direct coronary artery bypass grafting and to evaluate angiographic patency of anastomoses. METHODS A total of 120 patients (86 men) were operated on, with ages ranging from 30 to 83 years (mean = 61.2 years). Two access routes were used: for single left anterior descending coronary artery lesions an 8 cm anterior minithoracotomy was performed at the fourth left intercostal space. Extracorporeal circulation was not used. In the last 82 patients a restraining device was used for the regional reduction of heart beats. Coronary cineangiography was carried out between postoperative days 1 and 3 in 84 (70%) patients. Anastomoses were graded: grade A, no blocks; grade B, blocks of more than 50%; grade C, occlusion. This evaluation was performed for two different periods: in the first period a restraining device was not used and in the second period a restraining device was used. RESULTS In the first study period (38 anastomoses) coronary cineangiography showed grade A, 79%, grade B, 5.2%, and grade C, 15.8%. In the second study period (62 anastomoses), angiography showed grade A, 90.4%, grade B, 6.4%, and grade C, 3.2%. Early mortality was 1.6%. CONCLUSIONS Minimally invasive coronary artery bypass grafting is a good alternative for some groups of patients. Anastomotic results seem to be better when a restraining device is used.

Anterior cruciate ligament ganglion: case report

CONTEXT A ganglion is a cystic formation close to joints or tendinous sheaths, frequently found in the wrist, foot or knee. Intra-articular ganglia of the knee are rare, and most of them are located in the anterior cruciate ligament. The clinical picture for these ganglia comprises pain and movement restrictions in the knee, causing significant impairment to the patient. Symptoms are non-specific, and anterior cruciate ligament ganglia are usually diagnosed through magnetic resonance imaging or arthroscopy. Not all ganglia diagnosed through magnetic resonance imaging need to undergo surgical treatment: only those that cause clinical signs and symptoms do. Surgical results are considered good or excellent in the vast majority of cases. CASE REPORT A 29-year-old male presented with pain in the left knee during a marathon race. Physical examination revealed limitation in the maximum range of knee extension and pain in the posterior aspect of the left knee. Radiographs of the left knee were normal, but magnetic resonance imaging revealed a multi-lobed cystic structure adjacent to the anterior cruciate ligament, which resembled a ganglion cyst. The mass was removed through arthroscopy, and pathological examination revealed a synovial cyst. Patient recovery was excellent, and he resumed his usual training routine five months later.

Cerebral abscess caused by Serratia marcescens in a premature neonate

BACKGROUND Cerebral abscesses are extremely rare in neonates. Serratia marcescens is an unusual cause of sepsis and neurological spread is especially ominous. PURPOSE To report the case of a 34-week neonate who developed this rare condition and to discuss diagnostic and therapeutic measures. CASE REPORT A 34-week male neonate sequentially developed respiratory distress syndrome, early sepsis and necrotizing enterocolitis; later cultures revealed S. marcescens. After deterioration, a cerebral abscess became evident, which revealed S. marcescens. Clinical improvement ensued after high-dose amikacin and meropenem. CONCLUSION Clinical signs are often non-specific. Proper diagnostic measures, neurosurgical consultation and aggressive antibiotic therapy are essential for these high-risk neonates.

The connective tissue of the adductor canal – a morphological study in fetal and adult specimens

The adductor canal is a conical or pyramid‐shaped pathway that contains the femoral vessels, saphenous nerve and a varying amount of fibrous tissue. It is involved in adductor canal syndrome, a claudication syndrome involving young individuals. Our objective was to study modifications induced by aging on the connective tissue and to correlate them to the proposed pathophysiological mechanism. The bilateral adductor canals and femoral vessels of four adult and five fetal specimens were removed en bloc and analyzed. Sections 12 µm thick were obtained and the connective tissue studied with Sirius Red, Verhoeff, Weigert and Azo stains. Scanning electron microscopy (SEM) photomicrographs of the surfaces of each adductor canal were also analyzed. Findings were homogeneous inside each group. The connective tissue of the canal was continuous with the outer layer of the vessels in both groups. The pattern of concentric, thick collagen type I bundles in fetal specimens was replaced by a diffuse network of compact collagen bundles with several transversal fibers and an impressive content of collagen III fibers. Elastic fibers in adults were not concentrated in the thick bundles but dispersed in line with the transversal fiber system. A dynamic compression mechanism with or without an evident constricting fibrous band has been proposed previously for adductor canal syndrome, possibly involving the connective tissue inside the canal. The vessels may not slide freely during movement. These age‐related modifications in normal individuals may represent necessary conditions for this syndrome to develop.