godfather of surgery

Chapter 1394 Diagnosing Like Solving a Crime
Early in the morning, as usual, Zaxi arrived at the research institute at six o'clock. He sat down in the demonstration room, opened his notebook, and prepared to continue organizing the materials for Professor Zhou's case when his phone rang.

It's Professor Yang.

"Come to my office." The voice on the other end of the phone was calm, no different from usual.

Professor Yang, you're here so early today!

Zaxi closed his notebook and hurried toward Professor Yang's office. Yang Ping's office door was open, and he was standing in front of the whiteboard, but he wasn't looking at the clues in Professor Zhou's case. The whiteboard had been wiped clean, and new things had been written on it.

"Sit down!" Yang Ping pointed to a chair, sat down opposite him, and placed a printed medical record on the table.

Zaxi glanced at the medical record cover; it belonged to a patient in the neurology department of Sanbo Hospital. He looked up at Yang Ping, somewhat puzzled.

Yang Ping seemed to see through his thoughts and said, "The neurology department can't handle this patient, so they called a hospital-wide consultation. I looked at the data and found it interesting. You can come and participate in this consultation."

Zaxi was stunned: "Me?"

Yang Ping nodded: "Yes, you'll be in charge. From taking the patient's medical history, conducting a physical examination, ordering tests, to reviewing literature, analyzing diagnoses, and developing treatment plans, you'll do it all. I'll be watching, but I won't help you unless you make a fatal mistake."

Zaxi opened his mouth as if to say something, but Yang Ping had already pushed the medical record in front of him.

“You’ve learned something from Professor Zhou’s case: how to find the key chain of evidence from a bunch of seemingly unrelated clues. Now, apply that ability to patients. Solving cases and treating patients are essentially the same thing.”

"As for that case, you don't need to worry about it. That's a police matter. Our job is just to provide necessary medical advice."

Zaxi took a deep breath and opened the medical record. The first page contained basic information: the patient was a 43-year-old female, a local resident of Nandu, and a company employee. Chief complaint: recurrent headaches and blurred vision for three months, worsening with right-sided limb weakness for one week. He continued reading. The admission record stated that the patient began experiencing paroxysmal headaches three months prior, in varying locations, sometimes in the forehead, sometimes the back of the head. The pain was described as throbbing or pulsating, of moderate intensity, and tolerable. She also experienced blurred vision, seeing things as if through a fog. She had previously consulted another hospital, where a head CT scan was performed, which showed no abnormalities. The doctor diagnosed her with migraines and prescribed painkillers, but the effect was poor. A week ago, the headaches suddenly worsened, accompanied by right-sided limb weakness, difficulty holding objects, and a tendency to veer to the right when walking. A repeat head CT scan at another hospital also showed no abnormalities. The patient was transferred to the neurology department of Sanbo Hospital.

Zaxi turned to the next page, which contained the preliminary neurological examination record. Physical examination: The patient was alert and fluent in speech; both pupils were equal and round, reacting briskly to light; eye movements were free, and no nystagmus was observed. Right limb muscle strength was grade IV decreased, and left limb strength was grade V. The right Babinski sign was positive. Sensory examination was unremarkable. Coordination: The right finger-to-nose test and heel-to-shin test were both unreliable and inaccurate.

He frowned. The patient's symptoms were strange: headache, blurred vision, right-sided weakness, and ataxia, but the head CT scan was normal. A normal CT scan meant there was no obvious brain hemorrhage, brain tumor, or cerebral infarction. So what was it? He continued flipping through the pages of lab reports. Complete blood count, liver and kidney function, electrolytes, and coagulation function were all normal. All the routine tests were normal.

Zaxi looked up at Yang Ping and said, "Professor Yang, all the tests are normal."

Yang Ping nodded: "Yes, that's why the neurology department can't handle it."

Zaxi lowered his head again and continued flipping through the medical record. The next section was a record of a consultation between the neurology and ophthalmology departments. Ophthalmological examination: Visual acuity 0.6 in the right eye and 0.8 in the left eye, no improvement after correction. Fundus examination: Blurred margins of both optic discs, mild edema. The ophthalmological diagnosis was: Bilateral optic disc edema, cause to be determined.

Papilledema? This indicates increased intracranial pressure. However, the head CT scan is normal, and no space-occupying lesions are seen. So what is causing the increased intracranial pressure? He recalled a concept he learned in medical school: increased intracranial pressure with a normal CT scan could be caused by intracranial venous sinus thrombosis, meningitis, intracranial infection, metabolic diseases, etc.

Zaxi felt it was amazing. Ever since Professor Yang got him involved in that case, he no longer found these thick, complicated medical records boring. Instead, he felt a strange excitement and a desire to get the answers.

He continued flipping through the pages; the next page contained the lumbar puncture record. The neurology department had performed a lumbar puncture to measure intracranial pressure: 280 mmHg, while the normal range is 80 to 180. Zaxi's brow furrowed even more. The intracranial pressure was indeed elevated, and significantly so. However, the routine, biochemical, and cytological examinations of the cerebrospinal fluid were all normal. No infection, no tumor cells, no abnormalities.

He flipped through the entire medical record, leaned back in his chair, his mind a jumbled mess. A 43-year-old woman had been experiencing recurring headaches and blurred vision for three months, and a week prior, she developed right-sided limb weakness and ataxia. Increased intracranial pressure was detected, but a head CT scan, lumbar puncture, and all routine examinations were normal. What could this be?

Yang Ping sat opposite him, quietly watching him without saying a word. Zaxi knew that Yang Ping was waiting for him to speak.

“Professor Yang, I need to go see the patient.” Zaxi stood up.

Yang Ping nodded: "Go ahead, I'll wait for you in the office. Solving a case requires being at the scene in person, and we doctors must personally interact with patients. That's why we're called clinical doctors."

The neurology department is on the seventh floor of the inpatient ward at Sanbo Hospital. Zaxi walked through the corridor and found the patient's room. It was a three-person room, and the patient was in a window seat, bed number 26. When he pushed the door open, the patient was leaning against the headboard looking at her phone, and her husband was sitting next to her.

"Hello, I'm Dr. Zaxi, Professor Yang's student. I've come to see you." Zaxi tried to make his voice sound calm.

The patient looked up; she was a refined-looking woman wearing glasses, her face somewhat pale. She smiled, but her smile carried a hint of weariness: "Hello, Dr. Zaxi, you've been examining me for several days now, what exactly is wrong?"

Tashi didn't answer, but asked, "May I ask you a few questions first?"

The patient nodded, and Zaxi sat down, opened his notebook, and began asking about the patient's medical history. He asked very detailed questions: When did the headache start? What kind of pain was it? Where was it located? Were there any triggers? Was it accompanied by nausea and vomiting? How did the blurred vision appear? Was it sudden or gradual? Was there double vision? When did the weakness in the right limbs begin? Was it sudden or gradually worsening? Were there any sensory abnormalities? Were there any bowel or bladder dysfunctions? Had the patient had a cold, diarrhea, injury, or vaccination before the onset of symptoms? Was there a history of chronic diseases? Was there a history of long-term medication? Was there a family history of hereditary diseases?

Tashi was amazed at how meticulous and detailed he was in taking the patient's medical history; he used to be so forgetful.

The patient answered each question in turn. The headaches started three months ago without any obvious cause; it just started suddenly one morning when they woke up, and they assumed it was from lack of sleep. The headaches were intermittent, sometimes lasting a few days without pain, and sometimes lasting for several days in a row. The blurred vision also appeared gradually; initially, they thought their glasses were too weak, but getting new glasses didn't help. The weakness in their right limbs appeared suddenly a week ago; that morning, when they reached for a cup, it slipped from their hand, and they realized their right hand was weak. Their gait was also unsteady, like someone who was drunk. Before the onset of symptoms, they had no colds, diarrhea, injuries, or vaccinations. They had no history of high blood pressure, diabetes, or heart disease. They were not taking any long-term medications. Both parents were healthy, and there were no hereditary diseases.

Zaxi wrote down all the information, then stood up and said to the patient, "May I do another physical examination for you?"

The patient nodded. Zaxi examined him from head to toe. The pupils were equal and round, and reacted briskly to light. An ophthalmological examination revealed blurred margins and mild edema in both optic discs. Muscle strength on the right side was indeed grade IV decreased; the left hand was strong, but the right hand was weaker. The Babinski sign was positive on the right side. The finger-to-nose test—asking the patient to point to their nose with their right hand—was inaccurate and unsteady. The knee-to-shin test was similar; when the patient raised their right leg to try and reach their left knee, the finger wobbled.

After he finished his examination, he put the items away and said to the patient, "Thank you for your cooperation. I'll study it further when I get back."

Stepping out of the ward, Zaxi stood in the corridor, mentally reviewing the information he had gathered and the findings. A 43-year-old woman, with a subacute onset and progressive worsening, primarily presenting with increased intracranial pressure and right-sided cerebellar signs. Increased intracranial pressure included headache, papilledema, and elevated cerebrospinal fluid pressure. Right-sided cerebellar signs included right-sided ataxia, right-sided muscle weakness, and a positive Babinski sign on the right. However, the head CT scan was normal, routine lab tests were normal, and the cerebrospinal fluid analysis was normal. What could this be? A growth in the brain? But the CT scan was normal, showing no space-occupying lesion. Intracranial infection? But the cerebrospinal fluid was normal, showing no elevated cell count, no elevated protein, and no pathogens. Cerebrovascular disease? But the CT scan showed no hemorrhage or infarction. Demyelination disease? Multiple sclerosis? But the patient showed no signs of optic neuritis, no sensory abnormalities, and no spinal cord symptoms. Autoimmune disease? But the patient showed no joint pain, rash, or oral ulcers.

Zaxi returned to Yang Ping's office, sat down, and recounted everything he had found and thought of. Yang Ping listened without comment, only asking, "What do you plan to do?"

Zaxi thought for a moment and said, "I need to check the literature. This disease is too atypical. I need to see if there are any similar case reports."

Yang Ping nodded: "Okay, let me know when you've finished investigating."

Zaxi returned to the study room, turned on his computer, and began searching on PubMed. He used several keyword combinations—intracranial hypertension, cerebellar ataxia, normal CT, normal CSF. The search returned few articles, so he read through the titles and abstracts one by one.

After searching for about an hour, he found a case report from the journal *Neurology*, titled "A Case of Idiopathic Hypertrophic Dural Meningitis Presenting with Increased Intracranial Pressure and Cerebellar Ataxia." Zaxi opened the full text and quickly skimmed through it. The patient described in the case report was very similar to the patient he had seen in the ward: a middle-aged woman with a subacute onset, presenting with headache, blurred vision, and increased intracranial pressure, later developing cerebellar ataxia. A head CT scan and routine cerebrospinal fluid analysis were normal. Only after a contrast-enhanced MRI of the head was diffuse thickening and enhancement of the dura mater discovered. Zaxi was quite excited and continued reading. The article stated that hypertrophic dural meningitis is a rare disease with an unknown cause, possibly related to autoimmunity. Diffuse thickening of the dura mater compresses brain tissue and nerves, leading to increased intracranial pressure and various neurological symptoms. Diagnosis mainly relies on contrast-enhanced MRI of the head; thickening of the dura mater can be seen on T1-weighted images, with significant enhancement after contrast administration.

He put down the paper and searched for several related articles. One review stated that hypertrophic pachymeningitis presents with a variety of symptoms, including headache, blurred vision, double vision, hearing loss, cranial nerve palsy, cerebellar ataxia, and limb weakness. Because the symptoms are so atypical, it is often misdiagnosed. The key to diagnosis is to perform a contrast-enhanced MRI scan of the head.

Zaxi printed out the relevant literature and researched information on the etiology, pathology, diagnostic criteria, and treatment of hypertrophic pachymeningitis. He organized all the information into a folder and then drew a mind map in his notebook, listing all possible diagnoses centered on the patient's symptoms, and then eliminating them one by one using a process of elimination. In the end, only a few possibilities remained—hypertrophic pachymeningitis, intracranial venous sinus thrombosis, low intracranial pressure syndrome, and autoimmune meningitis. Intracranial venous sinus thrombosis could be ruled out using MRI. Low intracranial pressure syndrome could be ruled out because the patient's intracranial pressure was increased, not decreased. Autoimmune meningitis usually involves elevated cell counts or protein levels in the cerebrospinal fluid, but the patient's cerebrospinal fluid was normal, making it unlikely. Therefore, the most probable diagnosis was hypertrophic pachymeningitis.

He closed his notebook, glanced at his watch; it was already noon. He stood up, picked up the documents, and headed towards Yang Ping's office.

Yang Ping was eating in his office when he saw Zaxi come in. He put down his chopsticks and asked, "Did you find out?"

Zaxi placed the documents on the table and began his report. He explained all the information he had found, his analysis process, and the reasons for ruling out other diagnoses. Finally, he stated his conclusion: "Professor Yang, I suspect this patient has hypertrophic pachymeningitis and recommend a contrast-enhanced MRI of the head for confirmation."

Yang Ping listened without speaking immediately. He opened the documents and read them page by page. After about ten minutes, he looked up at Zaxi and said, "I basically agree with your reasoning. But there's one problem: the documents you found are all case reports from abroad. Hypertrophic pachymeningitis is very rare in China. Have you considered other, more common diagnoses?"

Zaxi thought for a moment and said, "I've considered it. Intracranial venous sinus thrombosis can be ruled out with an MRV test. Autoimmune meningitis is unlikely, as the patient's cerebrospinal fluid is normal. Low intracranial pressure syndrome is ruled out because the patient's intracranial pressure is increased, not decreased. Tuberculous meningitis is ruled out because the patient's cerebrospinal fluid is normal and there are no symptoms of tuberculosis poisoning. Tumor-related meningitis is also ruled out because the patient's cerebrospinal fluid is normal and there is no history of primary tumors."

He paused, then said, "There's another possibility—neurosarcoidosis. But sarcoidosis usually presents with symptoms in other systems, such as the lungs, skin, and joints. The patient doesn't have these symptoms. Also, the cerebrospinal fluid in sarcoidosis usually shows an elevated cell count or protein level, so it's unlikely since the patient's cerebrospinal fluid is normal."

Yang Ping nodded and said, "Your analysis is very comprehensive, but there is one diagnosis you did not consider."

Zaxi was stunned: "What?"

Yang Ping said, "Parasyte syndrome."

Tashi opened his mouth, but couldn't speak. "Parabolic syndrome," he explained, "is neurological damage caused by an immune system through a tumor, which can occur before the tumor is detected. It manifests in various ways, including cerebellar degeneration, limbic encephalitis, and peripheral neuropathy. The patient's subacute cerebellar ataxia does indeed match the presentation of paraneoplastic cerebellar degeneration, but paraneoplastic syndromes usually don't cause increased intracranial pressure." Tashi shared his thoughts.

Yang Ping nodded: "You're right. Paraneoplastic syndromes usually don't cause increased intracranial pressure. But this patient has increased intracranial pressure, so paraneoplastic syndromes are unlikely. However, you need to mention this differential diagnosis in your analysis and explain why you ruled it out. That's complete clinical thinking, considering all possibilities. This requires a very strong foundation of knowledge. Where does knowledge come from? Textbooks, literature, teachers' instruction, clinical experience..."

Tashi lowered his head and added a line to his notebook: Differential diagnosis: Paraneoplastic syndrome, ruled out due to increased intracranial pressure.

Yang Ping stood up and picked up the phone on the table: "Neurology? This is Yang Ping. The patient in ward seven, I suggest a contrast-enhanced MRI of the head, yes, and an MRV to rule out venous sinus thrombosis. Okay, thank you."

After hanging up the phone, he looked at Zaxi and said, "You'll have an MRI tomorrow morning. Once the results are in, you can analyze them."

Tashi nodded, feeling both nervous and expectant.

The following morning, Zaxi arrived at the MRI room early. Guided by a technician, the patient entered the scanning room. Zaxi stood in front of the glass window of the control room, watching the images appear on the screen bit by bit. The technician first performed a plain scan, then T1-weighted images, T2-weighted images, and FLAIR images, scanning layer by layer. Zaxi stared at the screen, his heart racing. Beside him was Dr. Fang Chuan from the radiology department.

The plain CT scan showed no obvious abnormalities in the brain parenchyma. There were no tumors, no infarctions, and no hemorrhages. Then the technician began the contrast-enhanced scan, injecting the contrast agent and waiting a few minutes before starting the scan. The enhanced images were displayed layer by layer.

Professor Yang is currently training him to read various images, including MRI scans, but he doesn't have that level of skill yet and needs Dr. Fang to provide him with the results.

Dr. Fang from the radiology department pointed to the image and said, "There is obvious linear enhancement at the top of the brain, along the dura mater of the falx cerebri and the convex surfaces of both cerebral hemispheres. The enhancement is very uniform and smooth, like a shell covering the surface of the brain."

Dr. Fang zoomed in on the image and looked at it again: "That's right, it's diffuse thickening and enhancement of the dura mater."

Tashi now understands the significance of studying at a top-tier hospital. Every specialty here has top experts, and by learning from them, he broadens his knowledge and skills, which naturally improves his abilities.

The technician continued scanning, and Dr. Fang continued examining the scan. Upon reaching the posterior fossa, the dura mater along the tentorium cerebelli and around the foramen magnum showed similar enhancement. The entire dura mater, from front to back and from left to right, was thickened and enhanced. This is the typical presentation of hypertrophic pachymeningitis.

Zaxi's hands began to tremble. His diagnosis was correct. He picked up his phone and sent a message to Yang Ping: "Professor Yang, the MRI results are in. Diffuse thickening and enhancement of the dura mater, consistent with hypertrophic pachymeningitis."

Yang Ping replied instantly: "Okay! Come to my office."

Zaxi ran to Yang Ping's office, pushed open the door, and found Yang Ping standing in front of the whiteboard with a marker in his hand. Seeing Zaxi enter, he said, "Draw out the MRI results."

Tashi took the pen and was stunned; he had no idea how to draw.

Yang Ping didn't blame him, but said gently, "So there's a lot you need to learn now, such as medical drawing, imaging, reading and analyzing test results, etc. You've already made a lot of progress in taking medical histories, but you still need to strengthen your physical examinations. Your independent analysis of auxiliary examinations is still lacking. The basis for diagnosing any patient is nothing more than medical history, physical examination, and auxiliary examinations. But this can't be rushed. The training plan I gave you includes all of these. As long as you can implement each one, these problems will be solved."

Zaxi's face was flushed. Yang Ping took the pen from him and quickly drew an anatomical diagram of the patient's head on the whiteboard: "The diagnosis is clear. Now what's the problem?"

Zaxi thought for a moment and said, "The cause of hypertrophic pachymeningitis can be idiopathic or secondary. Secondary causes include infection, tumors, and autoimmune diseases. Further investigation is needed to determine the cause."

Yang Ping nodded: "That's right. Apart from the diagnosis of the cause of the disease, most diagnoses do not actually identify the cause. We must take the diagnosis as the starting point and continue to deduce the cause as much as possible in the past, and then deduce the treatment plan, prognosis, and so on in the future. What should we investigate next?"

Tashi opened his notebook and read aloud the information he had found: "We need to check ANCA, ACE, antinuclear antibody, rheumatoid factor, immunoglobulin, complement, HIV, syphilis, and tuberculosis infection T-cell spot test. We also need to do a whole-body PET-CT to rule out potential tumors or sarcoidosis. If none of these are found, then it is idiopathic."

Yang Ping looked at him, a hint of approval in his eyes: "What about the treatment plan?"

Zaxi said, "Glucocorticoids, methylprednisolone pulse therapy, followed by slow tapering of oral prednisone. If the effect is not good, immunosuppressants such as cyclophosphamide, mycophenolate mofetil, and rituximab can be added."

"This is just routine treatment. We can't become good doctors if we're satisfied with just this," Yang Ping cautioned.

Tashi realized, "I need to check the literature to see if there are any more advanced treatment methods in the world."

Yang Ping nodded in satisfaction.