A Narrative Review of Stroke of Cortical Hand Knob Area.

The cortical hand knob region of the brain is a knob-like segment of the precentral gyrus, projecting into the middle genu of the central sulcus. This anatomic landmark is responsible for intricate control of hand motor movements and has often been implicated in motor weakness following stroke. In some instances, damage to this area has been mistaken for peripheral causes of hand weakness. Our article aims to consolidate clinically relevant information on the cortical hand knob area in a comprehensive review to guide clinicians regarding diagnosis and treatment strategies. We conducted a systematic search within the Medline/PubMed database for reports of strokes in the cortical hand knob region. All studies were published electronically up until December 2023. The search was conducted using the keyword "hand knob". A total of 24 reports containing 150 patients were found. The mean and median ages were 65 and 67 years, respectively. Sixty-two percent of the individuals were male. According to the TOAST criteria for the classification of the stroke, 59 individuals had a stroke due to large-artery atherosclerosis, 8 had small-vessel occlusion, 20 had cardioembolism, 25 were determined, and 38 were undetermined. The most common etiologies for stroke in the hand knob area can be attributed to large vessel occlusions, small vessel occlusions, or cardioembolism. Presentations following damage to this area can mimic ulnar, median, or radial neuropathy as well. Our comprehensive review serves as a resource for recognizing and managing stroke in the cortical hand knob area.

Radial nerve palsy caused by a rapidly growing intramuscular hematoma in an infant with biliary atresia: a case report.

BACKGROUND: Biliary atresia (BA) is a rare cause of persistent jaundice in infants that can result in vitamin K malabsorption and vitamin K deficiency bleeding (VKDB). We present an infant with BA who developed a rapidly growing intramuscular hematoma in her upper arm after a vaccination which caused a radial nerve palsy. CASE PRESENTATION: An 82-day-old girl was referred to our hospital because of a rapidly growing left upper arm mass. She had received three doses of oral vitamin K before age 1 month. At age 66 days, she received a pneumococcal vaccination in her left upper arm. On presentation, she showed no left wrist or finger extension. Blood examination revealed direct hyperbilirubinemia, liver dysfunction, and coagulation abnormalities, indicating obstructive jaundice. Magnetic resonance imaging showed a hematoma in the left triceps brachii. Abdominal ultrasonography revealed an atrophic gallbladder and the triangular cord sign anterior to the portal vein bifurcation. BA was confirmed on cholangiography. VKDB resulting from BA in conjunction with vaccination in the left upper arm were considered the cause of the hematoma. The hematoma was considered the cause of her radial nerve palsy. Although she underwent Kasai hepatic portoenterostomy at age 82 days, the obstructive jaundice did not sufficiently improve. She then underwent living-related liver transplantation at age 8 months. The wrist drop was still present at age 1 year despite hematoma resolution. CONCLUSIONS: Delayed detection of BA and inadequate prevention of VKDB can result in permanent peripheral neuropathy.

'Cortical Hand' in the Emergency Department: Two Case Reports.

BACKGROUND: Cortical hand strokes affect the 'hand knob' of the motor cortex, resulting in isolated distal upper limb or hand weakness. They are rare and can be easily misdiagnosed for peripheral lesions. CASE REPORTS: Case 1: A 59-year-old man presented to the Emergency Department (ED) after noticing left hand weakness while driving. There was no sensory deficit noted. A full neurological examination suggested an upper motor neurone rather than a peripheral nerve lesion. This was confirmed by a magnetic resonance imaging scan of his brain. Case 2: An 88-year-old man presented to the ED after developing sudden-onset left hand weakness while completing a newspaper puzzle. Power returned gradually over approximately 4 h, with no sensory symptoms being noted. A transient ischemic attack leading to cortical hand was diagnosed. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Cortical hand strokes are a rare, but important, differential for wrist drop. They are often first strokes and embolic in nature. Therefore, correct diagnosis is vital to enable initiation of secondary prevention.

Radial nerve palsy: If in doubt, use ultrasound.

Sonographic demonstration of radial nerve compression by a strict permanent suture, with intra-operative correlation.

Ultrasound of the Radial Nerve: A Pictorial Review.

This pictorial review focuses on the ultrasound (US) appearance of the normal and pathological radial nerve (RN) and its branches and provides tips with which to locate them and avoid misinterpretation of normal findings. A wide range of our pathological cases are reviewed and presented to help in familiarizing the reader with common and uncommon clinical scenarios that affect the RN and its main branches.

Evaluation of Extensor Pollicis Brevis as a Recipient of Tendon Transfer for Thumb Extension.

Introduction Rerouting of the extensor pollicis longus (EPL) is the standard part of tendon transfer surgery for thumb extension. It is done to overcome the ulnar vector of the EPL action. Extensor pollicis brevis (EPB), however, produces better thumb abduction and extension by virtue of its radial vector. The described anatomical variation of EPB extending the thumb interphalangeal joint (IPJ), therefore, gives the "best combination" of movements by a single-thumb extensor tendon. Materials and Methods We performed this transfer in six patients in whom the EPB was found to be extending the IPJ while checked intraoperatively. Three of these six patients were cases of radial nerve palsy and the other three presented with brachial plexus palsy. The outcome was assessed by measuring palmar and radial abduction of the thumb, Kapandji's score, and Bincaz's scale. Results We found satisfactory results in all the six patients. In our series, patients had an average radial extension of the thumb of 29.2 degrees and an average palmar abduction of the thumb of 65.7 degrees. On evaluation with the Bincaz score; one patient had excellent result, three patients had good results, and two patients had fair results. Conclusion In situations where EPL rerouting is not possible (as in cases where the donor tendon needs to reach the thumb from the ulnar side, for example, flexor carpi ulnaris), transfer to the EPB, provided it is extending the thumb IPJ, would produce better extension and abduction of the thumb than the transfer to the EPL.

New-Onset Wrist Drop After a Night of Drinking: A Case Report.

This case report highlights the clinical approach to evaluating a patient with substance use disorder presenting with a sudden onset of peripheral neuropathy in the left hand. Our patient had significant cardiovascular risk factors, which further broadened the differential diagnosis beyond common causes of mononeuropathy. The use of detailed and appropriate clinical history, physical examination, and careful selection of relevant laboratory and radiological tests was instrumental in ruling out multiple medical differential diagnoses, including common mononeuropathies and life-threatening ones, such as cerebrovascular accidents, which facilitated the involvement of necessary consults while also treating both the presenting medical complication and underlying severe alcohol use disorder with additional efforts at relapse prevention.

Radial neuropathy.

Radial neuropathy is the third most common upper limb mononeuropathy after median and ulnar neuropathies. Muscle weakness, particularly wrist drop, is the main clinical feature of most cases of radial neuropathy, and an understanding of the radial nerve's anatomy generally makes localizing the lesion straightforward. Electrodiagnosis can help confirm a diagnosis of radial neuropathy and may help with more precise localization of the lesion. Nerve imaging with ultrasound or magnetic resonance neurography is increasingly used in diagnosis and is important in patients lacking a history of major arm or shoulder trauma. Radial neuropathy most often occurs in the setting of trauma, although many other uncommon causes have been described. With traumatic lesions, the prognosis for recovery is generally good, and for patients with persistent deficits, rehabilitation and surgical techniques may allow substantial functional improvement.

Pseudoulnar palsy with concurrent wrist drop: case report.

Introduction and importance: Pseudoulnar palsy, characterized by weakness in the fourth and fifth digits, is a condition typically attributed to infarction of the medial aspect of the precentral gyrus's "hand knob." This anatomical site is located in the primary motor cortex of the brain, in the posterior lobe of the frontal cortex. This report presents a novel case of pseudoulnar nerve palsy in conjunction with wrist drop stemming from an infarction of the hand knob gyrus. Case presentation: A 78-year-old female with hypertension and hyperlipidemia experienced sudden right wrist weakness and impaired mobility in her fourth and fifth digits. Clinical examinations, including neuroimaging, supported the diagnosis of an infarction in the medial precentral gyrus. Brain MRI confirmed the diagnosis of an acute infarction in the medial precentral gyrus. The patient was treated with enoxaparin, aspirin, and dexamethasone, and was discharged after symptom improvement. Clinical discussion: Unlike the classical presentations, this case highlights the co-occurrence of ulnar and radial deficits following a unique infarction pattern. The distinct presentation of right pseudoulnar palsy with wrist drop was caused by an infarction at the level of the medial aspect of the hand knob. Conclusion: This case underscores the importance of considering the central causes of peripheral-like deficits, especially in older individuals with vascular risk factors, emphasizing the significance of early intervention in mitigating potential long-term consequences. This report contributes to the evolving understanding of central neurological presentations, and serves as a reminder of the need for a comprehensive diagnostic approach.

Hand Knob Syndrome Secondary to Ipsilateral Concomitant Carotid Fibromuscular Dysplasia and Proximal Atherosclerotic Disease.

One of the uncommon stroke presentations is the isolated wrist drop syndrome, caused by a stroke affecting the hand knob area, with the embolic mechanism being the most commonly identified mechanism. Here, we present the case of a 62-year-old female patient who presented with acute-onset isolated wrist drop secondary to right internal carotid artery fibromuscular dysplasia with a string of beads appearance and coexisting proximal atherosclerotic severe stenosis. The patient underwent successful carotid artery stenting. Patients with hand knob stroke may present a diagnostic dilemma and can be misdiagnosed as having peripheral neuropathy due to the absence of pyramidal signs and other symptoms of cortical involvement, leading to delayed or inappropriate treatment.

Isolated Wrist Drop as the Sole Presentation of an Acute Embolic Ischemic Stroke.

Stroke is a major public health concern and a leading cause of morbidity and mortality worldwide. It often presents with a wide range of neurological deficits based on the neuroanatomical locus of the insult. Symptoms widely vary and usually occur in concordance with the distribution of the homunculus. Although rare, stroke can present with isolated wrist drop, which creates a diagnostic dilemma owing to the fact that this condition is by far more commonly caused by peripheral lesions. Moreover, localizing the site of injury is crucial for guiding therapeutic management and determining the overall prognosis of the condition. We present a 73-year-old patient with an isolated central wrist drop caused by an embolic ischemic stroke that was initially confused for a lower motor neuron pathology affecting the radial nerve.

Bilateral Wrist Drop Due to Lead Poisoning in a Young Woman With Opium Addiction.

Opium addiction can cause symptoms in the central or peripheral neurological systems, as well as gastrointestinal disorders and anemia; in such situations, lead poisoning should be considered and chelation therapy should be started as soon as possible. In adults, lead poisoning is an unusual cause of abdominal pain. A common form of lead neuropathy includes weakness of the wrist and finger extensors. We describe a 24-year-old female who developed severe lead poisoning after 3 years of opium consumption, leading to gastrointestinal complaints and bilateral wrist drops.

Bilateral Wrist Drop Caused by Non-invasive Continuous Monitoring of Blood Pressure During Severe COVID-19 Pneumonia: A Case Report.

Compressive peripheral nerve injury can be observed as a long-term outcome during the treatment of severe COVID-19 pneumonia. In this case study, we report a man with bilateral wrist drop due to prolonged noninvasive blood pressure monitoring. A 52-year-old man who had undergone invasive ventilation because of severe COVID-19 pneumonia was admitted with bilateral loss of function of the wrist, digital, and thumb extensors and hypoesthesia in the dorsum of the forearm and hand. The patient had not been treated with prone positioning respiratory therapy. However, he had undergone bilateral automated sphygmomanometry that measured his blood pressure every ten minutes during his ICU stay. His electrophysiological findings were compatible with the presence of bilateral radial nerve compression at the level of the spiral groove. Awareness of potential compressive peripheral nerve injury is important for rehabilitation after the treatment of COVID-19-associated pneumonia.

Outcome of human amniotic membrane wrap around neurorrhaphy in high radial nerve injury - a case report following monkey bite.

INTRODUCTION: Peripheral nerve injury due to animal bite is a rare phenomenon. Most animal bites are from dogs. Monkey bites constitute a common risk, second only to dog bites, among travelers. Peripheral nerve injuries may occur due to a combination of monkey's strong jaws and sharp long teeth penetrating deep into the soft tissues. Such injuries are associated with increased perineural fibrosis. Human amniotic membrane (HAM) wrap around the nerve repair site reduces fibrotic response, prevents adhesions and scar formation thereby improving outcome. We report a case of "High Radial nerve palsy due to monkey bite, treated by neurorrhaphy with HAM wrap". METHOD: A 3-year old boy presented with wrist drop, and inability to extend the fingers and thumb of his right dominant hand, following a monkey bite over the distal arm. The diagnosis of high radial nerve injury was corroborated by high frequency ultrasound and electrodiagnostic studies. On exploration the radial nerve was found to be transected. An end to end repair was performed, with HAM wrap around the neurorrhaphy. RESULTS: Wrist dorsiflexion recovered at 2.5 months followed by active finger and thumb extension at 4 months with no infection or immune rejection. CONCLUSION: Nerve regeneration in our patient occurred at a faster rate as compared to the conventional 1 mm/day. This could be attributed to decreased perineural fibrosis, improved neurotropism due to the HAM wrap and neuronal plasticity in young brain in addition, the patient being a small child having better regenerative ability in comparison to an adult.

[Combined distal nerve and tendon transfer in drop wrist for treatment of high injuries of the radial nerve]. / Kombinierter distaler Nerven- und Sehnentransfer bei Fallhand zur Behandlung hoher Verletzungen des N. radialis.

OBJECTIVE: The aim of direct distal selective nerve transfer close to the end organ with high radial nerve injury is restoration of the paretic function before irreversible atrophy of the target muscle. Simultaneous tendon transfer enables direct functional correction of wrist drop. INDICATIONS: Selective nerve and tendon transfer of the lower arm is indicated if a) the primary nerve lesion is located proximally distant and reinnervation by direct nerve repair would take too long to reach a paretic muscle because of the long distance involved, b) direct repair of the nerve lesion is impossible or c) there has been a substantial delay after the primary injury. A viable donor nerve must be available. CONTRAINDICATIONS: A) After final denervation of a muscle, which occurs approximately 1.5 years after a nerve injury, the atrophy is irreversible and a nerve transfer can no longer restore the paretic muscle. Only younger patients under 30 years old might benefit from delayed nerve transfer. B) When no sufficient donor nerve is available only tendon transfer is possible. SURGICAL TECHNIQUE: Direct nerve transfer from the median nerve to the radial nerve as well as direct functional correction of wrist drop by tendon transfer of the pronator teres muscle. POSTOPERATIVE MANAGEMENT: Immobilization of the arm for 3 days, wrist orthosis for 6 weeks for protection of the tendon transfer, ergotherapy and physiotherapy preferably by a hand therapist. RESULTS: Active wrist and finger extension 2 years after transfer, with individualized extension of the thumb and index finger is possible, wrist drop reversed.

Diabetes Ketoacidosis Complicating as Wrist Drop: A Case Report on Acute Motor Neuropathy.

Diabetic ketoacidosis (DKA) is an acute and major complication of diabetes mellitus. Neurological complications can be seen at any time during the course of illness and range from decreased consciousness to ischemic or hemorrhagic stroke. Acute neuropathy is very rare in this milieu. Here, we report a case of a 40-year-old patient, who developed a left-sided wrist drop after being treated for DKA. The nerve conduction velocity studies demonstrated decreased action potential amplitude in only the motor component of the left radial nerve. Other possible causes of the complaint were ruled out and the patient was managed with cock-up splint, vitamin B1 and B6 supplementation, and physiotherapy. Despite all these measures, the patient had minimal improvement. Thus, close monitoring of patients is crucial to identify these infirmities, even after the acute condition has resolved.

"Cortical" Wrist Drop due to a Cerebral Peduncle Infarct.

Wrist drops are usually due to a peripheral neuropathy affecting the radial nerve. Cortical wrist drops may occur, usually due to a lesion in the contralateral hand area of the motor cortex. We report a unique case of "cortical" wrist drop due to an acute infarction of the contralateral cerebral peduncle. The patient is a 70-year-old gentleman with the vascular factors of hypertension, hyperlipidaemia, and prior cerebellar strokes, who developed sudden onset of right wrist weakness without numbness. Neurological examination showed a right wrist and finger drop. Nerve conduction study of the radial nerve was normal. MRI brain revealed an acute infarct in the medial part of the left cerebral peduncle, extending slightly to the medial thalamus; there were also old medial posterior cerebellar infarcts. Time of flight MR angiography was normal, with hypoplastic right vertebral artery. Echocardiography was normal but for a dilated right atrium. Electrocardiogram was normal, and 24-hour Holter monitoring detected infrequent atrial and ventricular ectopics. X-ray wrist showed an old ulnar styloid fracture. Nerve conduction study of the radial nerve was normal. He was switched from aspirin to clopidogrel and underwent rehabilitation. The cerebral peduncle should not be forgotten when attempting to anatomically localise the site of the lesion when evaluating a patient with a wrist drop.

Outcome of tendon transfer for radial nerve palsy using Flexor Carpi Radialis combination (Brands transfer).

INTRODUCTION: -Loss of radial nerve function leads to severe weakness of grip and tendon transfer is considered the standard treatment. However; there is continuing debate as to the best combination of tendon transfers in such patients. The aim of this study is to present the results of Flexor carpi radialis (FCR) combination of triple tendon transfer for radial nerve palsy. MATERIAL AND METHODS: It is a retrospective study conducted over 15 years. 58 patients of with irreversible radial nerve paralysis were included. Brands transfer was performed in all cases. The ranges of movement of the wrist, fingers and thumb were evaluated pre-operatively and postoperatively using Bincaz scale. RESULTS: Total 58 patients were included in the study, 47 were male and 11 female patients with mean age of 35.27 years. Causes of radial nerve palsy were comminuted open humeral fracture (n = 42), penetrating injuries (n = 13) and brachial plexus palsy (n = 3). Mean duration of palsy was 9.37 months (range = 9-12 months). The mean post-operative follow-up was 10 (range = 2-15) years. On evaluation with the Bincaz score, 6 patients had excellent results, 49 patients had good results, and 3 patients had poor results. There were 3 complications in 5 patients, including radial deviation of wrist, inadequate abduction of thumb and restricted wrist flexion. 55 patients (94.82%) were able to return to their normal daily work after ∼8 weeks. Conclusions - Tendon transfer is a standard procedure for radial nerve palsy but potential advantage of one method over the other has not been demonstrated. Brand's transfer results in an acceptable restoration of hand function.

Isolated Wrist Drop Presenting as Acute Stroke: Rare Case Report with Review of Literature.

Isolated wrist drop is very unusual clinical presentation due to cerebral stroke. It is highly confused with peripheral neuropathy. However, timely detection of acute stroke as one of the causes of wrist drop is necessary as it changes the line of treatment and prognosis significantly. Here we are presenting a 62 year-old diabetic and hypertensive male patient who came with acute onset weakness of right hand. Initial Magnetic resonance imaging (MRI) of the brain showed hyperacute infarct in the splenium of corpus callosum. Magnetic resonance angiography (MRA) was normal. Repeat brain MRI on next day showed acute infarct at hand area of motor strip in posterior frontal region. The patient underwent intravenous thrombolysis and thereafter improved significantly. Isolated hand palsy is a rare presentation of stroke, often mistaken for peripheral lesion.