Combined cervical laminoplasty and foraminotomy for coexistence of cervical myelopathy and unilateral radiculopathy: case series and preliminary results.

BACKGROUND: The clinical outcomes and radiographic changes of a one-stage procedure combining cervical laminoplasty and unilateral cervical foraminotomy for patients with coexisting cervical myelopathy and unilateral radiculopathy were evaluated. METHODS: Seven patients (two females and five males) with coexisting cervical myelopathy and unilateral cervical radiculopathy were included in this study. The mean age was 58.4 years (range 45-77 years). Cervical laminoplasty and unilateral cervical foraminotomy were performed on the recruited patients in a single stage. The quantitative clinical changes between the preoperative and 6-month postoperative assessment were analyzed using the Japanese Orthopedic Association (JOA) score, the JOA Cervical Myelopathy Evaluation Questionnaire (JOA-CMEQ), visual analog scale (VAS), and Neck Disability Index (NDI). Moreover, the preoperative and 6-month postoperative radiographic changes were assessed using the C2-7 angle and range of motion (ROM) between flexion and extension angle. RESULTS: There were significant differences in QOL in the JOA-CMEQ between the groups. Furthermore, the postoperative VAS values in the arms and hands generally improved, although not significantly, between the groups. CONCLUSIONS: The aforementioned surgical procedure may be safe and efficient for patients with coexisting cervical myelopathy and radiculopathy.

Intramedullary feeder aneurysm of a cervical epidural arteriovenous fistula causing myelopathy: a case report and literature review.

While a craniocervical junction (CCJ) epidural arteriovenous fistula (EDAVF) may present with hemorrhagic myelopathy from an associated feeder aneurysm on rare occasions, non-hemorrhagic myelopathy from such an aneurysm remains unreported. A woman in her late sixties presented with cervical myelopathy due to a non-hemorrhagic intramedullary aneurysm associated with CCJ-EDAVF. The intramedullary aneurysm originated from the spinal pial artery supplied by the anterior spinal artery. Direct surgical fistula coagulation and feeder obliteration resulted in the disappearance of the aneurysm and myelopathy improvement. This report illustrates the first case of a non-hemorrhagic intramedullary aneurysm associated with CCJ-EDAVF successfully treated with direct surgery.

A rare adult case of asymptomatic double aortic arch accompanied by the right vertebral artery directly originating from the aortic arch.

INTRODUCTION: A double aortic arch (DAA) is a rare congenital vascular anomaly. No case of DAA with a direct aortic origin of the right vertebral artery (VA) has been reported in adults. Here, we report a rare case of an asymptomatic DAA accompanied by the right VA directly originating from the right aortic arch in an adult. CASE PRESENTATION: A DAA and right VA directly originating from the right aortic arch were identified in a 63-year-old man using digital subtraction angiography and computed tomography angiography. The patient underwent digital subtraction angiography for evaluation of an unruptured cerebral aneurysm. Intraprocedural selection of vessels branching from the aorta with the catheter was difficult. To confirm the bifurcation of the aorta, aortography was performed, which revealed a DAA. Following digital subtraction angiography, computed tomography angiography was performed, which showed that the right VA originated directly from the right aortic arch. The trachea and esophagus were located in the vascular ring of the DAA; however, they were not compressed by the aorta. This was consistent with the lack of symptoms related to the DAA. CONCLUSIONS: This is the first adult case of an asymptomatic DAA with an unusual origin of the VA. A rare asymptomatic vascular anomaly, such as a DAA, can be incidentally identified using angiography.

Rare anastomosis between the bilateral internal carotid arteries via the recurrent arteries branching from the first segment of the ophthalmic artery.

Although anastomoses between the arterial branches arising from the internal carotid artery (ICA) can develop as collateral pathways between the bilateral ICAs in cases of dysgenesis of the ICA, anastomosis of the recurrent arteries branching from the first segment of the ophthalmic artery (OphA) has not been described. Herein, we report two cases of this rare anastomosis. In a 36-year-old man with left segmental dysgenesis of the ICA, an anastomosis between the bilateral ICAs developed around the sella turcica. In a 39-year-old woman with dysgenesis of the bilateral distal ICAs, an anastomosis between the superior hypophyseal trunk and bilateral ICAs was identified. The anastomoses in both cases were also supplied by recurrent arteries branching from the first segment of the OphAs. This is the first report describing recurrent arteries from the OphAs that form the anastomosis between bilateral ICAs.

Subjective and objective evaluation of swallowing in lateral decubitus positions examined in healthy volunteers.

BACKGROUND: Dysphagia can result from shock, trauma, aging, head and neck neoplasms, and some cerebrovascular diseases or neuromotor degenerative disorders. Swallowing rehabilitation therapy combined with postural control of the neck, head, and body can be effective for patients with dysphagia. Though the lateral decubitus posture has been a favorable option for swallowing rehabilitation therapy, available clinical data pertaining to it are scarce. METHODS: Twenty-seven healthy volunteers were enrolled in this study. The subjects underwent a repetitive saliva swallowing test, food swallowing test, and water swallowing test. The trials were performed in four different positions: upright sitting position, lateral decubitus position with the head raised to 60°, lateral decubitus position with the head raised to 30°, and complete lateral decubitus position. After each trial, the subjects were asked to declare the swallowing difficulty utilizing a visual analogue scale. Swallowing time and swallowing sound level were recorded simultaneously, as objective evaluation in each trial. We analyzed the visual analogue scale scores, swallowing time, and swallowing sound levels for all the four positions. RESULTS: The results of the visual analogue scale of the water swallowing test in the sitting position were significantly lower than those of the complete lateral decubitus position (p < 0.01). However, statistical significance was not detected in swallowing time or the swallowing sound level among the four different positions. Although subjective discomfort in swallowing was identified, difficulty of swallowing was not objectively evident in the trials, irrespective of the position. CONCLUSIONS: A complete lateral decubitus position can be an effective and safe position in swallowing.

Infratentorial developmental venous anomaly concurrent with a cavernoma and dural arteriovenous fistula.

OBJECTIVES: While developmental venous anomaly (DVA) may be associated with cavernous malformation, mixed vascular malformation associated with dural arteriovenous fistula (dAVF) has not been previously reported. We observed a case with rare association of infratentorial DVA, cavernous malformation, and dAVF that presented with cerebellar ataxia. We report our endovascular treatment for this complex cerebrovascular condition. CASE PRESENTATION: A 32-year-old woman with ataxia had an infratentorial DVA associated with a cavernoma and dAVF. The dAVF had two shunting points. The dAVF was fed by the posterior meningeal arteries and drained through the sigmoid sinus into the transverse sinus. The dAVF was also fed by the occipital artery and retrogradely drained through the left jugular bulb into the dilated collecting vein of the DVA. Endovascular embolization was performed for the dAVF and dilated collecting vein of the DVA. Postoperative complications did not occur after embolization with no recurrence for three years. CONCLUSIONS: This is the first reported case of infratentorial DVA associated with a cavernoma and dAVF. Endovascular treatment was effective in treating this symptomatic complex cerebrovascular disorder.

A Simple Surgical Technique for Pediatric Sinus Pericranii: Intraoperative Manual Compression of a Major Shunting Point.

INTRODUCTION: Sinus pericranii is a vascular anomaly with extra- and intracranial venous connections. Sinus pericranii is categorized into 2 groups according to its contribution to the normal venous circulation. The accessory type sinus pericranii, which does not contribute to the normal major venous circulation, can be managed. Despite several proposed operative maneuvers, a standardized technique is yet to be established to control intraoperative bleeding. CASE PRESENTATION: A 2-week-old neonate underwent examination of a subcutaneous mass in the parieto-occipital region. The subcutaneous mass had a major venous connection to the superior sagittal sinus on ultrasonography. The subcutaneous mass was partially thrombolized on magnetic resonance imaging and was minimally enhanced on computed tomography venography. The subcutaneous mass seemed not to contribute to the normal venous circulation. Surgical removal of the subcutaneous mass was performed due to its increased size at the age of 1 year and 3 months. While subcutaneous mass was detached from the scalp, the major venous connection was manually compressed, and minor venous connections were easily detected. The intraoperative bleeding was controllable. The pathological diagnosis was sinus pericranii. The patient is now followed up in the outpatient clinic. No recurrence was seen 18 months after the surgery. DISCUSSION/CONCLUSION: Intraoperative hemostasis is essential while sinus pericranii is detached from the cranium. Hemostatic agents such as bone wax or absorbable gelatin and heat coagulation seem to be useful. However, complicative hemorrhage concerning to the preceded technique has been also reported. As seen in our case, to detect minor shunting points between the sinus pericranii and the intracranial veins, the major venous connection was manually compressed. Intraoperative manual compression of a major venous connection of sinus pericranii can be an option to manage intraoperative bleeding.

The Use of the Carotid Sheath as a Rotation Anchor to Detect an Anomalous Ascending Pharyngeal Artery in Carotid Endarterectomy.

Carotid endarterectomy (CEA) requires complete control of the blood backflow. An anomalous ascending pharyngeal artery (AphA) has been reported to result in incomplete control of the blood flow during CEA. Here, we present a case of symptomatic right internal carotid stenosis for which CEA was performed. An anomalous AphA was confirmed based on its origin from the distal internal carotid artery (ICA) on 3-dimensional rotational angiography (3DRA). The anomalous AphA arose near the distal end of the plaque, and the origin of the AphA was located in the dorsal wall of the ICA, hidden from the surgical view. The origin of the AphA was detected with rotation of the ICA within the carotid sheath (CS). Intraoperatively, the blood flow from the AphA was completely controlled with clamping of the origin of the AphA. We emphasize the importance of the 3DRA to detect an anomalous AphA and propose the use of the CS as an anchor to rotate the ICA for optimizing the surgical view behind the ICA. This simple surgical technique facilitates to detect and clamp an anomalous AphA arising from the ICA.

Analysis of the sexual development-promoting region of Schizophyllum commune TRP1 gene.

This study aims to elucidate the mechanism of sexual development of basidiomycetous mushrooms from mating to fruit body formation. Sequencing analysis showed the TRP1 gene of basidiomycete Schizophyllum commune encoded an enzyme with three catalytic regions of GAT (glutamine amidotransferase), IGPS (indole-3-glycerol phosphate synthase), and PRAI (5-phosphoribosyl anthranilate isomerase); among these three regions, the trp1 mutant (Trp(-)) had a missense mutation (L→F) of a 338th amino acid residue of the TRP1 protein within the IGPS region. To investigate the function of IGPS region related to sexual development, dikaryons with high, usual, and no expression of the IGPS region of TRP1 gene were made. The dikaryotic mycelia with high expression of the IGPS formed mature fruit bodies earlier than those with usual and no expression of the IGPS. These results showed that the IGPS region in TRP1 gene promoted sexual development of S. commune.

["True" mixed pial-dural arteriovenous malformation: a case report].

Mixed pial-dural arteriovenous malformation(AVM) is currently defined as a malformation fed by both the pial and meningeal arteries. Although many cases of mixed pial-dural AVM have been reported, few papers have addressed its pathological locations. The authors report a case of a 43-year-old male patient with mixed pial-dural AVM in the occipital lobe, consisting of two distinct nidi located on the tentorium and in the cerebral parenchyma respectively. The lesions were surgically resected, and the pathological examination confirmed that both were indeed AVM. The authors discuss this rare type of AVM, focusing on the possible pathogenic mechanism thereof.

Two-Stage Cervical and Thoracic-Lumbar-Sacral Circumferential Fixation for Pyogenic Spondylitis: A Case Report.

Pyogenic spondylitis is a rare life-threatening condition. Conservative treatment with antibiotics is indicated; however, surgery can be considered in refractory cases. The surgical strategy varies, as pyogenic spondylosis can occur from the cervical to sacral regions. To our knowledge, although there is less invasiveness as an advantage in the following management, cervical and thoracic-lumbar-sacral circumferential fixations in two sessions for pyogenic spondylitis have not been previously described. An 84-year-old man complained of ambulation disturbances and pain in the neck and upper and lower extremities (the Japan Orthopaedic Association cervical myelopathy evaluation questionnaire score of 5/17). Magnetic resonance imaging revealed pyogenic spondylitis of the cervical, thoracic, and lumbar regions. Epidural abscesses and spondylodiscitis were concurrently diagnosed with multi-level skipping lesions from the cervical to the sacral regions. As these lesions were resistant to antibiotic treatment and the neurological symptoms worsened, surgical treatment was planned. Anterior cervical discectomy and fusion, and posterior cervical fixation were followed by oblique and posterior lumbar intervertebral fusions with long-level fixation from T12 to the ilium using percutaneous pedicle screws. The surgeries were performed in two sessions to avoid the invasiveness of surgeries in a single session. The patient's condition improved after a second surgery. The patient was discharged on postoperative day 116. No recurrence was observed for six months, and the patient was able to ambulate independently. Two-stage cervical and thoracic-lumbar-sacral circumferential fixation for pyogenic spondylitis contributed to a favorable outcome (the Japan Orthopaedic Association cervical myelopathy evaluation questionnaire score of 13/17).

L5 Nerve Root Radiculopathy as a Rare Complication Following Oblique Lateral Interbody Fusion at L5/S1 Combined With Posterior Fixation via Percutaneous Pedicle Screws for Adult Spinal Deformity.

Oblique lateral interbody fusion (OLIF) is an established and less invasive surgical approach for patients with adult spinal deformities. This method can also be applied to the L5/S1 region (termed "OLIF51"); however, reports on L5 nerve root radiculopathy as a rare complication of OLIF51 are limited. Here, we present the case of a 77-year-old woman with progressive adult spinal deformity who was followed up after an initial OLIF for the L3/4 and L4/5 levels. An additional operation was performed to resolve ambulation difficulty and back pain related to adult spinal deformity. Circumferential fixation was performed over two sessions. Initially, OLIF51 was performed concurrently with OLIF for L1/2 and L2/3. Eight days later, posterior fixation surgery from T10 to the ilium via percutaneous pedicle screws was performed. Two days after the second operation, the patient started complaining of left L5 nerve root radiculopathy, for which medication and rehabilitation were both ineffective. Retrospectively, we identified that the left L5/S1 foramen narrowed after the lordotic correction by OLIF51 and posterior fixation. Additionally, posterior facetectomy for L5/S1 was performed, and the left L5 nerve root radiculopathy was resolved. L5 nerve root radiculopathy can develop as a rare complication of OLIF51. Neurosurgeons should be aware of this rare complication related to OLIF51.

Unexpected coil mass migration during transvenous embolization of a dural arteriovenous fistula resolved with guidewire-assisted snaring technique.

Endovascular embolization is a standard treatment for dural arteriovenous fistulas (dAVFs). Although it is considered relatively safe, intraoperative and postoperative complications can occur. Herein, a rare case of unexpected coil mass migration requiring a retrieval procedure during sinus occlusion for a transverse-sigmoid sinus dAVF (TSdAVF) is described. An 83-year-old man presented with worsening decline in cognitive function. Magnetic resonance angiography showed a TSdAVF. Since his symptoms seemed to be a result of the TSdAVF, transvenous embolization preserving the normal cranial venous circulation was planned. During sinus occlusion, including embolization of the shunted pouch of the TSdAVF, unexpected migration of the coil mass to the confluence of the superior sagittal sinus and the transverse sinus occurred. The migrated coil mass impeded venous circulation in the superior sagittal sinus. Since the presence of the coil mass at the confluence could have had catastrophic sequelae, the coil mass was retrieved using a guidewire-assisted snaring technique. Sinus occlusion was subsequently completed with repositioning of the coil mass at the target site. The TSdAVF resolved, with no recurrence confirmed for 1 year. Clinicians should be aware that coil mass migration can unexpectedly occur during sinus occlusion performed for treatment of a TSdAVF. The guidewire-assisted snaring technique might be effective in resolving this intraoperative complication.

Chronic Subdural Hematoma in a Middle-Aged Amateur Scuba Diver: A Case Report.

Scuba diving has become a common and popular activity, and adverse events can occur following this activity. Among those events, intracranial hemorrhage is very rare, and only intracerebral hemorrhage and subarachnoid hemorrhage are reported. However, the occurrence of chronic subdural hematoma (CSDH), possibly as an adverse event following scuba diving, has not been described. A 49-year-old man with no significant medical history visited our hospital complaining of memory disturbance and aphasia. He had experienced a minor head trauma five months before and had gone scuba diving six times between the traumatic episode and the visit to our hospital. A brain computed tomography scan revealed a left CSDH. The patient underwent burr-hole surgery to remove the CSDH, and his symptoms resolved. We report the first case of CSDH possibly related to scuba diving. No recurrence of CSDH was observed at 28 months postoperatively.

Delayed Diagnosis of Spinal Cord Injury in a Patient With Intellectual Disability: A Case Report.

Spinal cord injury (SCI) can cause neurogenic shock accompanied by bradycardia and hypotension. If no preceding traumatic episodes are apparent and the neurological examination is complicated by the patient's intellectual disability, SCI is likely to be overlooked. A 63-year-old man with intellectual disability presented to our hospital. The patient had fallen on the floor; however, no apparent head or neck trauma was observed. The patient returned home after confirming the absence of intracranial hematoma on computed tomography. However, the patient was re-admitted because of hypotension and bradycardia, and sick sinus syndrome was suspected. As the manifestations were motor weakness in the extremities and urinary retention, screening spinal magnetic resonance imaging revealed cervical cord injury and spondylosis. Cervical SCI related to a fall was suspected. Cervical decompression surgery and rehabilitation therapy contributed to the improved patient status. Herein, we report a case of intellectual disability in which SCI was initially overlooked. No severe preceding traumatic episode or intellectual disability of the patient could have led to overlooking SCI in our case. Clinicians should be cautious about this rare condition.

An extremely rare complication during carotid artery stenting using a Wallstent: Migration of a stent holder of a Carotid Wallstent.

BACKGROUND: Carotid artery stenting (CAS) is an established treatment for internal carotid artery stenosis (ICS). The Carotid Wallstent is commonly used as a stent device in CAS procedures. Rare complications associated with the use of the Carotid Wallstent in CAS procedures include delayed shortening and incomplete stent expansion due to displacement of a marker ring. However, there have been no previous reports of a stent holder becoming unpredictably detached from a Carotid Wallstent during a procedure, requiring the additional deployment of another Carotid Wallstent. CASE PRESENTATION: The case of a 72-year-old man with progressive ICS is described. Since the ICS was resistant to medical treatment, CAS was planned to prevent ischemic events. During the procedure, a Mo.Ma Ultra and a carotid guardwire were used for proximal and distal protection, respectively. Following the introduction of those protective devices, a Carotid Wallstent was deployed at the stenotic lesion of the ICS. After the deployment of the Carotid Wallstent, a stent holder unpredictably detached was identified in the lumen of the Carotid Wallstent. Since it was impossible to mechanically retrieve the detached stent holder, another Carotid Wallstent was deployed to trap the substance. Postoperatively, the substance was identified as a stent holder of the first Carotid Wallstent. CONCLUSION: This is the first report of an extremely rare complication concerning a Carotid Wallstent in CAS.

Diffusion tensor imaging combined with the dual-echo steady-state (DESS) protocol for the evaluation of the median nerve in the carpal tunnel: A preliminary study.

Background: Carpal tunnel syndrome (CTS) is diagnosed based on neurological, electrophysiology, and radiological findings. Due to the technical development of magnetic resonance imaging (MRI), the median nerve is evaluated with several MRI protocols. However, diffusion tensor imaging (DTI) combined with a dual-echo steady-state (DESS) protocol is not frequently used to evaluate the median nerve of CTS. This study aimed to evaluate the median nerve in the carpal tunnel using DTI combined with a DESS protocol. Methods: Five healthy volunteers and seven patients with CTS were enrolled. The patients underwent MRI for CTS pre- and post-operatively. The median nerve was evaluated using a 3-T MRI scanner. The parameters of the DESS protocol were as follows: Repetition time (TR)/echo time (TE) = 10.83/3.32 ms, slice thickness = 0.45 mm, field of view (FoV) = 350 × 253 × 350 mm, and 3D voxel size = 0.5 × 0.5 ×0.4 mm. The parameters of the DTI sequence were as follows: TR/TE = 4000/86 ms, slice thickness = 3 mm, FoV = 160 × 993 × 90 mm, 3D voxel size = 1.2 × 1.2 ×3.0 mm, and b value = 0.1000 s/mm2. The apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values of the median nerve were statistically analyzed. Statistical significance was set at P< 0.05. Results: The FA value of healthy volunteers was 0.576 ± 0.058, while those of the patients were 0.357 ± 0.094 and 0.395 ± 0.062 pre-and post-operatively, respectively. Statistically significant differences were identified between the FA values of healthy volunteers and pre-operative/post-operative patients. The ADC values of healthy volunteers and pre-operative patients were 0.931 ± 0.096 and 1.26 ± 0.282 (10-3 mm2/s), respectively (P< 0.05). Conclusion: This MRI protocol may be useful for evaluating the median nerve in the carpal tunnel.

Factors Related to Favorable Outcomes in Older Adults Undergoing Home-Visit Rehabilitation Therapy.

BACKGROUND: Increasing elderly population is a major health concern worldwide, requiring various at-home care services. The aim of home-visit rehabilitation therapy is to support at-home living of the elderly and to promote their participation in social activities. There is a paucity of data about the clinical conditions of this population that can contribute to the achievement of goals in-home visit rehabilitation therapy. AIM: This study aimed to clarify clinical variables that could be related to the achievement of goals in-home visit rehabilitation therapy. METHODS: We collected retrospective clinical data of the older adults who underwent home-visit rehabilitation therapy between July 2006 and June 2021. We searched the clinical variables of home-visit rehabilitation therapy users and their frequency of utilization of home-visit rehabilitation therapy services from the clinical record. The initial and final clinical variables evaluated in this study included the abilities of daily living, degree of being bedridden, dementia rating, and levels of support or long-term care. Those variables were evaluated by rehabilitation therapists and doctors. The users were divided into three groups according to the reason for terminating rehabilitation therapy: goal achievement (achieved group), aggravation of underlying disease (aggravated group), and treatment suspension because of their own/others' wish (suspended group). The clinical parameters concerning the rehabilitation program, care level, and activities of daily living were evaluated among the groups. The clinical parameters concerning the rehabilitation program, care level, and activities of daily living were statistically evaluated among those three groups, using the chi-square test and Kruskal-Wallis test. RESULTS: In the achieved, aggravated, and suspended groups, 45, 190, and 38 users were respectively enrolled. The aggravated group showed significantly higher final care level (p = 0.002), degree of being bedridden (p=0.001), and dementia rating (p = 0.017) and significantly lower Barthel index scores (p < 0.001) and Frenchay Activities Index scores (p = 0.001) than the achieved group. Persons requesting the therapy were significantly older adults themselves in the achieved group (p = 0.018). The therapy was significantly performed more than once per week in the achieved group (p = 0.018). CONCLUSIONS: Older adults undergoing self-motivated home-visit rehabilitation therapy more than once per week may contribute to the achievement of the goal.

Risk of Bone Wax Migration During Retrosigmoid Craniotomy for Microvascular Decompression: Case-Control Study.

BACKGROUND AND OBJECTIVES: Bone wax is a flexible hemostatic agent commonly used for surgery in the posterior cranial fossa to control bleeding from the mastoid emissary vein. A large amount of bone wax can migrate into the sigmoid sinus through the mastoid emissary canal (MEC). We aimed to identify clinical factors related to intraoperative bone wax migration through the MEC during microvascular decompression (MVD) surgery, which may result in sigmoid sinus thrombosis. METHODS: We retrospectively collected the clinical data of patients with trigeminal neuralgia, hemifacial spasm, or trigeminal neuralgia accompanied by painful tic convulsif who underwent MVD. Basic information and the residual width and length (from the bone surface to the sigmoid sinus) of the MEC on computed tomography images were collected. We compared the collected clinical data between 2 groups of cases with and without intraoperative bone wax migration in the sigmoid sinus. RESULTS: Fifty-four cases with intraoperative bone wax migration and 187 patients without migration were enrolled. The t -test revealed significant differences in the width and length of the MEC ( P = .013 and P = .003, respectively). These variables were identified as significant factors in predicting intraoperative bone wax migration using multivariate logistic regression analysis. CONCLUSION: The large size of the MEC may be related to intraoperative bone wax migration into the sigmoid sinus in MVD. Neurosurgeons should be aware of these risks. Bone wax should be applied appropriately and hemostasis should be considered to control bleeding from the mastoid emissary vein in patients with a large MEC.

A Novel Method for Acquired Sex Chromosome Mosaicism.

The phenomenon of sex chromosome loss from hematopoietic cells is an emerging indicator of biological aging. While many methods to detect this loss have been developed, enhancing the field, these existing methods often suffer from being labor-intensive, expensive, and not sufficiently sensitive. To bridge this gap, a novel and more efficient technique is developed, named the SinChro assay. This method employs multiplexed single-cell droplet PCR, designed to detect cells with sex chromosome loss at single-cell resolution. Through the SinChro assay, the age-dependent increase in Y chromosome loss in male blood is successfully mapped. The age-dependent loss of the X chromosome in female blood is also identified, a finding that has been challenging with existing methods. The advent of the SinChro assay marks a significant breakthrough in the study of age-related sex mosaicism. Its utility extends beyond blood analysis, applicable to a variety of tissues, and it holds the potential to deepen the understanding of biological aging and related diseases.